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path: root/drivers/dma/pl330.c
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2015-09-04Merge tag 'dmaengine-4.3-rc1' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull dmaengine updates from Vinod Koul: "This time we have aded a new capability for scatter-gathered memset using dmaengine APIs. This is supported in xdmac & hdmac drivers We have added support for reusing descriptors for examples like video buffers etc. Driver will follow The behaviour of descriptor ack has been clarified and documented New devices added are: - dma controller in sun[457]i SoCs - lpc18xx dmamux - ZTE ZX296702 dma controller - Analog Devices AXI-DMAC DMA controller - eDMA support for dma-crossbar - imx6sx support in imx-sdma driver - imx-sdma device to device support Other: - jz4780 fixes - ioatdma large refactor and cleanup for removal of ioat v1 and v2 which is deprecated and fixes - ACPI support in X-Gene DMA engine driver - ipu irq fixes - mvxor fixes - minor fixes spread thru drivers" [ The Kconfig and Makefile entries got re-sorted alphabetically, and I handled the conflict with the new Intel integrated IDMA driver by slightly mis-sorting it on purpose: "IDMA64" got sorted after "IMX" in order to keep the Intel entries together. I think it might be a good idea to just rename the IDMA64 config entry to INTEL_IDMA64 to make the sorting be a true sort, not this mismash. Also, this merge disables the COMPILE_TEST for the sun4i DMA controller, because it does not compile cleanly at all. - Linus ] * tag 'dmaengine-4.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (89 commits) dmaengine: ioatdma: add Broadwell EP ioatdma PCI dev IDs dmaengine :ipu: change ipu_irq_handler() to remove compile warning dmaengine: ioatdma: Fix variable array length dmaengine: ioatdma: fix sparse "error" with prep lock dmaengine: hdmac: Add memset capabilities dmaengine: sort the sh Makefile dmaengine: sort the sh Kconfig dmaengine: sort the dw Kconfig dmaengine: sort the Kconfig dmaengine: sort the makefile drivers/dma: make mv_xor.c driver explicitly non-modular dmaengine: Add support for the Analog Devices AXI-DMAC DMA controller devicetree: Add bindings documentation for Analog Devices AXI-DMAC dmaengine: xgene-dma: Fix the lock to allow client for further submission of requests dmaengine: ioatdma: fix coccinelle warning dmaengine: ioatdma: fix zero day warning on incompatible pointer type dmaengine: tegra-apb: Simplify locking for device using global pause dmaengine: tegra-apb: Remove unnecessary return statements and variables dmaengine: tegra-apb: Avoid unnecessary channel base address calculation dmaengine: tegra-apb: Remove unused variables ...
2015-08-19dmaengine: pl330: do not emit loop for 1 byte transfer.Michal Suchanek
When there is only one burst required do not emit loop instructions to loop exactly once. Emit just the body of the loop. Signed-off-by: Michal Suchanek <hramrach@gmail.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-07-07dmaengine: pl330: Really fix choppy sound because of wrong residue calculationKrzysztof Kozlowski
When pl330 driver was used during sound playback, after some time or after a number of plays the sound became choppy or totally noisy. For example on Odroid XU3 board the first four executions of aplay with small WAVE worked fine, but fifth was unrecognizable with errors: $ aplay /usr/share/sounds/alsa/Front_Right.wava underrun!!! (at least 0.095 ms long) Issue was caused by wrong residue reported by pl330 driver to pcm_dmaengine for its cyclic dma transfers. The pl330_tx_status(), residue reporting function, used a "last" flag in a descriptor to indicate that there is no more data to send. The pl330_tx_submit() iterated over descriptors trying to remove this flag from them and then mark last descriptor as "last". However when iterating it actually removed the flag not from descriptors but always from last of it (and then reset it). Thus effectively once some descriptor was marked as last, then it stayed like this forever causing residue to be reported too low. Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com> Fixes: aee4d1fac887 ("dmaengine: pl330: improve pl330_tx_status() function") Cc: <stable@vger.kernel.org> Reported-by: gabriel@unseen.is Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-07-07dmaengine: pl330: Fix overflow when reporting residue in memcpyKrzysztof Kozlowski
During memcpy operations the residue was always set to an u32 overflowed value. In pl330_tx_status() function number of currently transferred bytes was subtracted from internal "bytes_requested" field. However this "bytes_requested" was not initialized at start to length of memcpy buffer so transferred bytes were subtracted from 0 causing overflow. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: <stable@vger.kernel.org> Fixes: aee4d1fac887 ("dmaengine: pl330: improve pl330_tx_status() function") Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-06-29Merge tag 'dmaengine-4.2-rc1' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull dmaengine updates from Vinod Koul: "This time we have support for few new devices, few new features and odd fixes spread thru the subsystem. New devices added: - support for CSRatlas7 dma controller - Allwinner H3(sun8i) controller - TI DMA crossbar driver on DRA7x - new pxa driver New features added: - memset support is bought back now that we have a user in xdmac controller - interleaved transfers support different source and destination strides - supporting DMA routers and configuration thru DT - support for reusing descriptors - xdmac memset and interleaved transfer support - hdmac support for interleaved transfers - omap-dma support for memcpy Others: - Constify platform_device_id - mv_xor fixes and improvements" * tag 'dmaengine-4.2-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (46 commits) dmaengine: xgene: fix file permission dmaengine: fsl-edma: clear pending interrupts on initialization dmaengine: xdmac: Add memset support Documentation: dmaengine: document DMA_CTRL_ACK dmaengine: virt-dma: don't always free descriptor upon completion dmaengine: Revert "drivers/dma: remove unused support for MEMSET operations" dmaengine: hdmac: Implement interleaved transfers dmaengine: Move icg helpers to global header dmaengine: mv_xor: improve descriptors list handling and reduce locking dmaengine: mv_xor: Enlarge descriptor pool size dmaengine: mv_xor: add support for a38x command in descriptor mode dmaengine: mv_xor: Rename function for consistent naming dmaengine: mv_xor: bug fix for racing condition in descriptors cleanup dmaengine: pl330: fix wording in mcbufsz message dmaengine: sirf: add CSRatlas7 SoC support dmaengine: xgene-dma: Fix "incorrect type in assignement" warnings dmaengine: fix kernel-doc documentation dmaengine: pxa_dma: add support for legacy transition dmaengine: pxa_dma: add debug information dmaengine: pxa: add pxa dmaengine driver ...
2015-06-08dmaengine: pl330: fix wording in mcbufsz messageMichal Suchanek
The kernel is not trying to increase mcbufsz. It suggests you should try doing so. Also print the calculated required size of mcbufsz. Signed-off-by: Michal Suchanek <hramrach@gmail.com> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-25dmaengine: pl330: Initialize pl330 for pl330_prep_dma_memcpy after NULL ↵Maninder Singh
check of pch Currently pch pointer is already dereferenced before NULL check and thus we are getting below warning: warn: variable dereferenced before check 'pch' So initialize struct pl330_dmac *pl330 after NULL check of dma_pl330_chan *pch. Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Reviewed-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-22dmaengine: pl330: Fix hang on dmaengine_terminate_all on certain boardsKrzysztof Kozlowski
The pl330 device could hang infinitely on certain boards when DMA channels are terminated. It was caused by lack of runtime resume when executing pl330_terminate_all() which calls the _stop() function. _stop() accesses device register and can loop infinitely while checking for device state. The hang was confirmed by Dinh Nguyen on Altera SOCFPGA Cyclone V board during boot. It can be also triggered with: $ echo 1 > /sys/module/dmatest/parameters/iterations $ echo dma1chan0 > /sys/module/dmatest/parameters/channel $ echo 1 > /sys/module/dmatest/parameters/run $ sleep 1 $ cat /sys/module/dmatest/parameters/run Reported-by: Dinh Nguyen <dinguyen@opensource.altera.com> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Fixes: ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12") Cc: <stable@vger.kernel.org> Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-03-18dmaengine: pl330: fix return status on pending transfersBen Dooks
The pl330_tx_status() function returns the desc->status if the dma_cookie_status() call does indicate the cookie completed, however the desc->status is not look directly compatible. Sparse throws the following warning: pl330.c:2262:35: warning: mixing different enum types pl330.c:2262:35: int enum desc_status versus pl330.c:2262:35: int enum dma_status Attempt to fix this by adding a switch statement to turn the desc->status into a dma_status. Note, this has only been tested with the dmatest suite. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> -- Vinod Koul <vinod.koul@intel.com> Dan Williams <dan.j.williams@intel.com> DMA List <dmaengine@vger.kernel.org> Maxime Ripard <maxime.ripard@free-electrons.com> Jassi Brar <jassisinghbrar@gmail.com> Liviu Dudau <Liviu.Dudau@arm.com> Linux ARM Kernel <linux-arm-kernel@lists.infradead.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-03-18dmaengine: pl330: make unexported functions staticBen Dooks
Whilst running sparse on pl330 driver it was noticed there are two functions that are not static but not exported to any other users in the kernel. Fix the following warnings by making 'pl330_pause' and the 'pl330_get_current_xferred_count' static: pl330.c:2165:5: warning: symbol 'pl330_pause' was not declared. Should it be static? pl330.c:2206:5: warning: symbol 'pl330_get_current_xferred_count' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> -- Vinod Koul <vinod.koul@intel.com> Dan Williams <dan.j.williams@intel.com> DMA List <dmaengine@vger.kernel.org> Maxime Ripard <maxime.ripard@free-electrons.com> Jassi Brar <jassisinghbrar@gmail.com> Liviu Dudau <Liviu.Dudau@arm.com> Linux ARM Kernel <linux-arm-kernel@lists.infradead.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-03-18dmaengine: pl330: fix issues with big-endian armv7Ben Dooks
When running Xilinx Zynq in big-endian mode the pl330 driver fails to pass the dmatest suite. To fix this, ensure all non byte values are written in little endian. As a note, the documentation does not mention if it will do big-endian descriptor fetches, only that it will swap the data in flight. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> -- Vinod Koul <vinod.koul@intel.com> Dan Williams <dan.j.williams@intel.com> DMA List <dmaengine@vger.kernel.org> Maxime Ripard <maxime.ripard@free-electrons.com> Jassi Brar <jassisinghbrar@gmail.com> Liviu Dudau <Liviu.Dudau@arm.com> Linux ARM Kernel <linux-arm-kernel@lists.infradead.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-02-16dmaengine: pl330: add DMA_PAUSE featureRobert Baldyga
DMA_PAUSE command is used for halting DMA transfer on chosen channel. It can be useful when we want to safely read residue before terminating all requests on channel. Otherwise there can be situation when some data is transferred before channel termination but after reading residue, which obviously results with data loss. To avoid this situation we can pause channel, read residue and then terminate all requests. This scenario is common, for example, in serial port drivers. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-02-16dmaengine: pl330: improve pl330_tx_status() functionRobert Baldyga
This patch adds possibility to read residue of DMA transfer. It's useful when we want to know how many bytes have been transferred before we terminate channel. It can take place, for example, on timeout interrupt. Signed-off-by: Lukasz Czerwinski <l.czerwinski@samsung.com> Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-02-10dmaengine: pl330: fix bug that cause start the same descs in cyclicAddy Ke
This bug will cause NULL pointer after commit dfac17, and cause wrong package in I2S DMA transfer before commit dfac17. Tested on RK3288-pinky2 board. Detail: I2S DMA transfer(sound/core/pcm_dmaengine.c): dmaengine_pcm_prepare_and_submit --> dmaengine_prep_dma_cyclic --> pl330_prep_dma_cyclic --> the case: 1. pl330_submit_req(desc0): thrd->req[0].desc = desc0, thrd->lstenq = 0 2. pl330_submit_req(desc1): thrd->req[1].desc = desc1, thrd->lstenq = 1 3. _start(desc0) by submit_req: thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 0 4. pl330_update(desc0 OK): thrd->req[0].desc = NULL, desc0 to req_done list because: idx = active = thrd->req_running = 0 5. _start(desc1) by pl330_update: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL, so: idx = thrd->lstenq = 1 6. pl330_submit_req(desc2): thrd->req[0].desc = desc2, thrd->lstenq = 0 7. _start(desc1) by submit_req: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 1 Note: _start started the same descs _start should start desc2 here, NOT desc1 8. pl330_update(desc1 OK): thrd->req[1].desc = NULL, desc1 to req_done list because: idx = active = thrd->req_running = 1 9. _start(desc2) by pl330_update : thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 0 10.pl330_update(desc1 OK, NOT desc2): thrd->req[0].desc = NULL, desc2 to req_done list because: idx = active = thrd->req_running = 0 11.pl330_submit_req(desc3): thrd->req[0].desc = desc3, thrd->lstenq = 0 12.pl330_submit_req(desc4): thrd->req[1].desc = desc4, thrd->lstenq = 1 13._start(desc3) by submit_req: thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 0 14.pl330_update(desc2 OK NOT desc3): thrd->req[0].desc = NULL desc3 to req_done list because: idx = active = thrd->req_running = 0 15._start(desc4) by pl330_update: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL, so: idx = thrd->lstenq = 1 16.pl330_submit_req(desc5): thrd->req[0].desc = desc5, thrd->lstenq = 0 17._start(desc4) by submit_req: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 1 18.pl330_update(desc3 OK NOT desc4): thrd->req[1].desc = NULL desc4 to req_done list because: idx = active = thrd->req_running = 1 19._start(desc4) by pl330_update: thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 1, but thrd->req[1].desc == NULL, so: idx = thrd->lstenq = 0 20.pl330_update(desc4 OK): thrd->req[0].desc = NULL, desc5 to req_done list because: idx = active = thrd->req_running = 0 21.pl330_update(desc4 OK): 1) before commit dfac17(set req_running -1 in pl330_update/mark_free()): because: active = -1, abort result: desc0-desc5's callback are all called, but step 10 and step 18 go wrong. 2) before commit dfac17: idx = active = thrd->req_runnig = 0 --> descdone = thrd->req[0] = NULL --> list_add_tail(&descdone->rqd, &pl330->req_done); --> got NULL pointer!!! Signed-off-by: Addy Ke <addy.ke@rock-chips.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-12-22dmaengine: pl330: Declare slave capabilities for the generic codeMaxime Ripard
Now that the generic slave caps code can make use of the device assigned capabilities, instead of relying on a callback to be implemented. Make use of this code. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-12-22dmaengine: pl330: Split device_controlMaxime Ripard
Split the device_control callback of the AMBA PL330 DMA driver to make use of the newly introduced callbacks, that will eventually be used to retrieve slave capabilities. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-12-22dmaengine: Make the destination abbreviation coherentMaxime Ripard
The dmaengine header abbreviates destination as at least two different strings. Make a coherent use of a single one. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-12-12Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM updates from Russell King: "The major updates included in this update are: - Clang compatible stack pointer accesses by Behan Webster. - SA11x0 updates from Dmitry Eremin-Solenikov. - kgdb handling of breakpoints with read-only text/modules - Support for Privileged-no-execute feature on ARMv7 to prevent userspace code execution by the kernel. - AMBA primecell bus handling of irq-safe runtime PM - Unwinding support for memset/memzero/memmove/memcpy functions - VFP fixes for Krait CPUs and improvements in detecting the VFP architecture - A number of code cleanups (using pr_*, removing or reducing the severity of a couple of kernel messages, splitting ftrace asm code out to a separate file, etc.) - Add machine name to stack dump output" * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (62 commits) ARM: 8247/2: pcmcia: sa1100: make use of device clock ARM: 8246/2: pcmcia: sa1111: provide device clock ARM: 8245/1: pcmcia: soc-common: enable/disable socket clocks ARM: 8244/1: fbdev: sa1100fb: make use of device clock ARM: 8243/1: sa1100: add a clock alias for sa1111 pcmcia device ARM: 8242/1: sa1100: add cpu clock ARM: 8221/1: PJ4: allow building in Thumb-2 mode ARM: 8234/1: sa1100: reorder IRQ handling code ARM: 8233/1: sa1100: switch to hwirq usage ARM: 8232/1: sa1100: merge GPIO multiplexer IRQ to "normal" irq domain ARM: 8231/1: sa1100: introduce irqdomains support ARM: 8230/1: sa1100: shift IRQs by one ARM: 8229/1: sa1100: replace irq numbers with names in irq driver ARM: 8228/1: sa1100: drop entry-macro.S ARM: 8227/1: sa1100: switch to MULTI_IRQ_HANDLER ARM: 8241/1: Update processor_modes for hyp and monitor mode ARM: 8240/1: MCPM: document mcpm_sync_init() ARM: 8239/1: Introduce {set,clear}_pte_bit ARM: 8238/1: mm: Refine set_memory_* functions ARM: 8237/1: fix flush_pfn_alias ...
2014-12-12Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull dmaengine updates from Vinod Koul: "Main features this time are: - BAM v1.3.0 support form qcom bam dma - support for Allwinner sun8i dma - atmels eXtended DMA Controller driver - chancnt cleanup by Maxime - fixes spread over drivers" * 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (56 commits) dmaenegine: Delete a check before free_percpu() dmaengine: ioatdma: fix dma mapping errors dma: cppi41: add a delay while setting the TD bit dma: cppi41: wait longer for the HW to return the descriptor dmaengine: fsl-edma: fixup reg offset and hw S/G support in big-endian model dmaengine: fsl-edma: fix calculation of remaining bytes drivers/dma/pch_dma: declare pch_dma_id_table as static dmaengine: ste_dma40: fix error return code dma: imx-sdma: clarify about firmware not found error Documentation: devicetree: Fix Xilinx VDMA specification dmaengine: pl330: update author info dmaengine: clarify the issue_pending expectations dmaengine: at_xdmac: Add DMA_PRIVATE ARM: dts: at_xdmac: fix bad value of dma-cells in documentation dmaengine: at_xdmac: fix missing spin_unlock dmaengine: at_xdmac: fix a bug in transfer residue computation dmaengine: at_xdmac: fix software lockup at_xdmac_tx_status() dmaengine: at_xdmac: remove chancnt affectation dmaengine: at_xdmac: prefer usage of readl/writel_relaxed dmaengine: xdmac: fix print warning on dma_addr_t variable ...
2014-12-05dmaengine: pl330: update author infoJassi Brar
Update email-id to a personal one, as I have changed employment. Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-11-27ARM: 8206/1: dmaengine: pl330: Add PM sleep supportKrzysztof Kozlowski
Add system suspend/resume capabilities to the pl330 driver so the amba bus clock could be also unprepared to conserve energy. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-11-17ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12Krzysztof Kozlowski
This patch adds runtime PM support to pl330 DMA engine driver. The runtime power management for pl330 DMA driver allows gating of AMBA clock (PDMA) in FSYS clock domain, when the device is not processing any requests. This is necessary to enter low power modes on Exynos SoCs (e.g. LPA on Exynos4x12 or W-AFTR on Exynos3250). Runtime PM resuming of the device may happen in atomic context (during call device_issue_pending()) so pm_runtime_irq_safe() is used. This will lead only to disabling/enabling of the clock but this is sufficient for gating the clock and for reducing energy usage. Driver uses runtime PM callbacks from amba/bus.c driver only. Suggested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-11-17dmaengine: pl330: Correct device assignment.Andrew Jackson
Commit f6f2421c0a1c removed pl330_info structure by embedding it into pl330_dmac structure, but did not ensure that the dmac->ddma.dev pointer gets initialised before use. When dma_alloc_coherent() gets called on arm64 a WARN() gets triggered due to dev being NULL. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1 at arch/arm64/mm/dma-mapping.c:49 __dma_alloc_coherent+0xd0/0xe0() Use an actual device structure for DMA allocation Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.17.0+ #5 Call trace: [<ffffffc000087f24>] dump_backtrace+0x0/0x130 [<ffffffc000088064>] show_stack+0x10/0x1c [<ffffffc0004e8af8>] dump_stack+0x74/0xb8 [<ffffffc0000aa444>] warn_slowpath_common+0x8c/0xb4 [<ffffffc0000aa4b8>] warn_slowpath_fmt+0x4c/0x58 [<ffffffc000092580>] __dma_alloc_coherent+0xcc/0xe0 [<ffffffc000092734>] __dma_alloc_noncoherent+0x64/0x158 [<ffffffc000312cd8>] pl330_probe+0x650/0x8f0 [<ffffffc00030e1d4>] amba_probe+0xa0/0xc8 [<ffffffc000350240>] really_probe+0xc4/0x22c [<ffffffc0003504b4>] __driver_attach+0xa0/0xa8 [<ffffffc00034e5fc>] bus_for_each_dev+0x54/0x98 [<ffffffc00034fd8c>] driver_attach+0x1c/0x28 [<ffffffc00034fa08>] bus_add_driver+0x14c/0x204 [<ffffffc000350b84>] driver_register+0x64/0x130 [<ffffffc00030dcf8>] amba_driver_register+0x50/0x5c [<ffffffc0006a60d0>] pl330_driver_init+0x10/0x1c [<ffffffc0000814ac>] do_one_initcall+0x88/0x19c [<ffffffc00068dab8>] kernel_init_freeable+0x140/0x1e0 [<ffffffc0004e5e18>] kernel_init+0x10/0xd4 ---[ end trace 76f2d47a444e523e ]--- (NULL device *): dmac_alloc_resources:1821 Can't allocate memory! (NULL device *): Unable to create channels for DMAC This patch will also ensure that any dev_err messages are printed with the appropriate device name. Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-11-17dmaengine: Fix allocation size for PL330 data buffer depth.Liviu Dudau
The datasheet for PL330 says that the data buffer value in the CRD register is 10bits wide. However, the value stored is "minus one", which the driver corrects for. Maximum value that the data buffer depth can have is 1024 lines, which requires 11 bits for storage. While making updates I found printing the peripheral ID as a hex value to be more useful as the datasheet shows the values that way. Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-11-17dmaengine: pl330: Limit MFIFO usage for memcpy to avoid exhausting entriesJon Medhurst
The MFIFO is shared by all channels so restrict each memcpy to it's fair share. This is being over cautious, but without a global view of DMA channel usage on a system it's not possible to come up with a more optimum safe limit. Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-11-17dmaengine: pl330: Align DMA memcpy operations to MFIFO widthJon Medhurst
The algorithm used for programming the DMA Controller doesn't take into consideration the requirements of transfers that are not aligned to the bus width. This failure may result in DMA transferring one too few MFIFO entries (so too few bytes are copied) or the DMA trying to write one too many MFIFO entries and hanging because this is never provided. See "MFIFO Usage Overview" chapter in the the TRM for "CoreLink DMA Controller DMA-330", Revision r1p1. We work around these shortcomings by making sure we pick a burst size and length which ensures no bursts straddle an MFIFO entry. Signed-off-by: Jon Medhurst <tixy@linaro.org> [squashed linker error "undefined reference to `__aeabi_uldivmod] Reported-by: kbuild test robot <fengguang.wu@intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-15dmaengine: pl330: Fix NULL pointer dereference on driver unbindKrzysztof Kozlowski
Fix a NULL pointer dereference after unbinding the driver, if channel resources were not yet allocated (no call to pl330_alloc_chan_resources()): $ echo 12850000.mdma > /sys/bus/amba/drivers/dma-pl330/unbind [ 13.606533] DMA pl330_control: removing pch: eeab6800, chan: eeab6814, thread: (null) [ 13.614472] Unable to handle kernel NULL pointer dereference at virtual address 0000000c [ 13.622537] pgd = ee284000 [ 13.625228] [0000000c] *pgd=6e1e4831, *pte=00000000, *ppte=00000000 [ 13.631482] Internal error: Oops: 17 [#1] PREEMPT SMP ARM [ 13.636859] Modules linked in: [ 13.639903] CPU: 0 PID: 1 Comm: sh Not tainted 3.17.0-rc3-next-20140904-00004-g7020ffc33ca3-dirty #420 [ 13.649187] task: ee80a800 ti: ee888000 task.ti: ee888000 [ 13.654589] PC is at _stop+0x8/0x2c8 [ 13.658131] LR is at pl330_control+0x70/0x2e8 [ 13.662468] pc : [<c0206028>] lr : [<c020649c>] psr: 60000093 [ 13.662468] sp : ee889e58 ip : 00000001 fp : 000bab70 [ 13.673922] r10: eeab6814 r9 : ee16debc r8 : 00000000 [ 13.679131] r7 : eeab685c r6 : 60000013 r5 : ee16de10 r4 : eeab6800 [ 13.685641] r3 : 00000002 r2 : 00000000 r1 : 00010000 r0 : 00000000 [ 13.692153] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user [ 13.699357] Control: 10c5387d Table: 6e28404a DAC: 00000015 [ 13.705085] Process sh (pid: 1, stack limit = 0xee888240) [ 13.710466] Stack: (0xee889e58 to 0xee88a000) [ 13.714808] 9e40: 00000002 eeab6800 [ 13.722969] 9e60: ee16de10 eeab6800 ee16de10 60000013 eeab685c c020649c 00000000 c040280c [ 13.731128] 9e80: ee889e80 ee889e80 ee16de18 ee16de10 eeab6880 eeab6814 00200200 eeab68a8 [ 13.739287] 9ea0: 00100100 c0208048 00000000 c0409fc4 eea80800 eea808f8 c0605c44 0000000e [ 13.747446] 9ec0: 0000000e eeb3960c eeb39600 c0203c48 eea80800 c0605c44 c0605a8c c023f694 [ 13.755605] 9ee0: ee80a800 eea80834 eea80800 c023f704 ee80a800 eea80800 c0605c44 c023e8ec [ 13.763764] 9f00: 0000000e ee149780 ee29e580 ee889f80 ee29e580 c023e19c 0000000e c01167e4 [ 13.771923] 9f20: c01167a0 00000000 00000000 c0115e88 00000000 00000000 ee0b1a00 0000000e [ 13.780082] 9f40: b6f48000 ee889f80 0000000e ee888000 b6f48000 c00bfadc 00000000 00000003 [ 13.788241] 9f60: 00000000 00000000 00000000 ee0b1a00 ee0b1a00 0000000e b6f48000 c00bfdf4 [ 13.796401] 9f80: 00000000 00000000 ffffffff 0000000e b6f48000 b6edc5d0 00000004 c000e7a4 [ 13.804560] 9fa0: 00000000 c000e620 0000000e b6f48000 00000001 b6f48000 0000000e 00000000 [ 13.812719] 9fc0: 0000000e b6f48000 b6edc5d0 00000004 0000000e b6f4c8c0 000c3470 000bab70 [ 13.820879] 9fe0: 00000000 bed2aa50 b6e18bdc b6e6b52c 60000010 00000001 c0c0c0c0 c0c0c0c0 [ 13.829058] [<c0206028>] (_stop) from [<c020649c>] (pl330_control+0x70/0x2e8) [ 13.836165] [<c020649c>] (pl330_control) from [<c0208048>] (pl330_remove+0xb0/0xdc) [ 13.843800] [<c0208048>] (pl330_remove) from [<c0203c48>] (amba_remove+0x24/0xc0) [ 13.851272] [<c0203c48>] (amba_remove) from [<c023f694>] (__device_release_driver+0x70/0xc4) [ 13.859685] [<c023f694>] (__device_release_driver) from [<c023f704>] (device_release_driver+0x1c/0x28) [ 13.868971] [<c023f704>] (device_release_driver) from [<c023e8ec>] (unbind_store+0x58/0x90) [ 13.877303] [<c023e8ec>] (unbind_store) from [<c023e19c>] (drv_attr_store+0x20/0x2c) [ 13.885036] [<c023e19c>] (drv_attr_store) from [<c01167e4>] (sysfs_kf_write+0x44/0x48) [ 13.892928] [<c01167e4>] (sysfs_kf_write) from [<c0115e88>] (kernfs_fop_write+0xc0/0x17c) [ 13.901090] [<c0115e88>] (kernfs_fop_write) from [<c00bfadc>] (vfs_write+0xa0/0x1a8) [ 13.908812] [<c00bfadc>] (vfs_write) from [<c00bfdf4>] (SyS_write+0x40/0x8c) [ 13.915850] [<c00bfdf4>] (SyS_write) from [<c000e620>] (ret_fast_syscall+0x0/0x30) [ 13.923392] Code: e5813010 e12fff1e e92d40f0 e24dd00c (e590200c) [ 13.929467] ---[ end trace 10064e15a5929cf8 ]--- Terminate the thread and free channel resource only if channel resources were allocated (thread is not NULL). Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: <stable@vger.kernel.org> Fixes: b3040e40675e ("DMA: PL330: Add dma api driver") Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-15dmaengine: pl330: Fix NULL pointer dereference on probe failureKrzysztof Kozlowski
If dma_async_device_register() returns error and probe should clean up and return error, a NULL pointer exception happens because of dereference of not allocated channel thread: Dmesg log (from early printk): dma-pl330 12680000.pdma: unable to register DMAC DMA pl330_control: removing pch: eeac4000, chan: eeac4014, thread: (null) Unable to handle kernel NULL pointer dereference at virtual address 0000000c pgd = c0004000 [0000000c] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc3-next-20140904-00005-g6cc4c1937d90-dirty #427 task: ee80a800 ti: ee888000 task.ti: ee888000 PC is at _stop+0x8/0x2c8 LR is at pl330_control+0x70/0x2e8 pc : [<c0205dc8>] lr : [<c020623c>] psr: 60000193 sp : ee889df8 ip : 00000002 fp : 00000000 r10: eeac4014 r9 : ee0e62bc r8 : 00000000 r7 : eeac405c r6 : 60000113 r5 : ee0e6210 r4 : eeac4000 r3 : 00000002 r2 : 00000002 r1 : 00010000 r0 : 00000000 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 4000404a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xee888240) Stack: (0xee889df8 to 0xee88a000) 9de0: 00000002 eeac4000 9e00: ee0e6210 eeac4000 ee0e6210 60000113 eeac405c c020623c 00000000 c020725c 9e20: ee889e20 ee889e20 ee0e6210 eeac4080 00200200 00100100 eeac4014 00000020 9e40: ee0e6218 c0208374 00000000 ee9bb340 ee0e6210 00000000 00000000 c0605cd8 9e60: ee970000 c0605c84 ee9700f8 00000000 c05c4270 00000000 00000000 c0203b3c 9e80: ee970000 c06624a8 00000000 c0605c84 00000000 c023f890 ee970000 c0605c84 9ea0: ee970034 00000000 c05b23d0 c023fa3c 00000000 c0605c84 c023f9b0 c023e0d4 9ec0: ee947e78 ee9b9440 c0605c84 eea1e780 c0605acc c023f094 c0513b50 c0605c84 9ee0: c05ecbd8 c0605c84 c05ecbd8 ee11ba40 c0626500 c0240064 00000000 c05ecbd8 9f00: c05ecbd8 c0008964 c040f13c 0000009f c0626500 c057465c ee80a800 60000113 9f20: 00000000 c05efdb0 60000113 00000000 ef7fc89d c0421168 0000008f c003787c 9f40: c0573d6c 00000006 ef7fc8bb 00000006 c05efd50 ef7fc800 c05dfbc4 00000006 9f60: c05c4264 c0626500 0000008f c05c4270 c059b518 c059bcb4 00000006 00000006 9f80: c059b518 c003c08c 00000000 c040091c 00000000 00000000 00000000 00000000 9fa0: 00000000 c0400924 00000000 c000e7b8 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0 [<c0205dc8>] (_stop) from [<c020623c>] (pl330_control+0x70/0x2e8) [<c020623c>] (pl330_control) from [<c0208374>] (pl330_probe+0x594/0x75c) [<c0208374>] (pl330_probe) from [<c0203b3c>] (amba_probe+0xb8/0x120) [<c0203b3c>] (amba_probe) from [<c023f890>] (driver_probe_device+0x10c/0x22c) [<c023f890>] (driver_probe_device) from [<c023fa3c>] (__driver_attach+0x8c/0x90) [<c023fa3c>] (__driver_attach) from [<c023e0d4>] (bus_for_each_dev+0x54/0x88) [<c023e0d4>] (bus_for_each_dev) from [<c023f094>] (bus_add_driver+0xd4/0x1d0) [<c023f094>] (bus_add_driver) from [<c0240064>] (driver_register+0x78/0xf4) [<c0240064>] (driver_register) from [<c0008964>] (do_one_initcall+0x80/0x1d0) [<c0008964>] (do_one_initcall) from [<c059bcb4>] (kernel_init_freeable+0x108/0x1d4) [<c059bcb4>] (kernel_init_freeable) from [<c0400924>] (kernel_init+0x8/0xec) [<c0400924>] (kernel_init) from [<c000e7b8>] (ret_from_fork+0x14/0x3c) Code: e5813010 e12fff1e e92d40f0 e24dd00c (e590200c) ---[ end trace c94b2f4f38dff3bf ]--- This happens because the necessary resources were not yet allocated - no call to pl330_alloc_chan_resources(). Terminate the thread and free channel resource only if channel thread is not NULL. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: <stable@vger.kernel.org> Fixes: 0b94c5771705 ("DMA: PL330: Add check if device tree compatible") Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-15dmaengine: pl330: Remove unused 'regs' variable in pl330_submit_req()Krzysztof Kozlowski
The 'void __iomem *regs' is not used in pl330_submit_req() function. Remove it. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-15dmaengine: pl330: Remove non-NULL check for pl330_submit_req parametersKrzysztof Kozlowski
The pl330_submit_req() checked supplied 'struct pl330_thread thrd' and 'struct dma_pl330_desc desc' parameters for non-NULL. However these checks are useless because supplied arguments won't be NULL. The pl330_submit_req() is called in only one place and: 1. 'desc' is already dereferenced in fill_queue() before calling pl330_submit_req(). 2. 'thrd' is always dereferenced after calling fill_queue()->pl330_submit_req(). Removing the checks for non-NULL values fixes following warning: drivers/dma/pl330.c:1376 pl330_submit_req() warn: variable dereferenced before check 'thrd' (see line 1367) Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-08-04dmaengine: Remove the context argument to the prep_dma_cyclic operationLaurent Pinchart
The argument is always set to NULL and never used. Remove it. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-22dmaengine: pl330: Check if the DMA descriptor is NULLJavier Martinez Canillas
Commit 6079d38 ("dmaengine: pl330: Remove useless xfer_cb indirection") removed the __callback() function which created an unnecessary level of indirection to execute the tranfer callback .xfer_cb Unfortunately the commit also changed the semantics slightly since that function used to check if the request was not NULL before attempting to execute the callback function. Not checking this could lead to a kernel NULL pointer dereference error. Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Acked-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove pl330_chan_ctrl()Lars-Peter Clausen
The pl330_chan_ctrl() function has 3 internal code paths which, except for the locking, do not share any code outside of their sections. One code path is never exercised and can be removed. The other two are mostly just forwards to the _start() and _stop() calls. This patch modifies the code to instead of going via pl330_chan_ctrl() to call _start() and _stop() directly. This allows to completely remove pl330_chan_ctrl(). Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Simplify marking a request as unusedLars-Peter Clausen
Instead of storing a special instruction in the command buffer to mark a request as currently unused just set the descriptor field to NULL. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Embed pl330_req directly into dma_pl330_descLars-Peter Clausen
The pl330_req struct is embedded into the dma_pl330_desc struct. But half of the pl330_req struct are pointers to other fields of the dma_pl330_desc struct it is embedded to. By directly embedding the fields from the pl330_req struct into the dma_pl330_desc struct and reworking the code to work with the dma_pl330_desc struct those pointers can be eliminated. This slightly simplifies the code. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Merge dma_pl330_dmac and pl330_dmac structsLars-Peter Clausen
Both the dma_pl330_dmac and the pl330_dmac struct have the same lifetime and the separation of them is a relict of this having been two different drivers in the past. Merging them into one struct makes the code a bit simpler as it for example allows to remove the pointers going back and forth between the two structs. While we are at it also directly embed the pl330_info struct into the pl330_dmac struct as this allows to remove some more redundant fields. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Simplify is_manager()Lars-Peter Clausen
Since we keep a pointer to the manager thread it is fairly easy to check if a thread is the manager thread. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove uneccessary ccr validationLars-Peter Clausen
We know that we do not create invalid ccr settings in this driver. There is no need to validate them. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Change type pl330_chid from void * to struct pl330_thread *Lars-Peter Clausen
The pl330_chid field of the dma_pl330_chan struct always holds a pointer to the thread that is associated with the channel. Changing its type form void * to struct pl330_thread makes things more type safe and removes the need for unnecessary typecasts. While we are at it also rename the field from the cryptic pl330_chid to thread. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove useless xfer_cb indirectionLars-Peter Clausen
The xfer_cb callback of the pl330_req struct is always set to the same function. This adds an unnecessary step of indirection. Instead just call the callback function directly. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove unused mc_len field from _pl330_req structLars-Peter Clausen
The mc_len is initialized but its value is never read again, so remove it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove unused next field form pl330_xfer structLars-Peter Clausen
The next field is always NULL, so we can remove it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove unused client_data field form pl330_infoLars-Peter Clausen
The field is completely unused, remove it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove unused dmac_reset callbackLars-Peter Clausen
The dmac_reset() callaback of the pl330_info struct is always set to NULL, so remove it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove unused pl330_chanstatus structLars-Peter Clausen
The pl330_chanstatus struct is completely unused, so remove it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Remove duplicated cachecontrol enumLars-Peter Clausen
The settings for destination and source cache control are exactly the same. This patch removes the duplicated enum and uses the same for both destination and source cache control. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15dmaengine: pl330: Use dma_transfer_direction instead of custom pl330_reqtypeLars-Peter Clausen
The pl330 driver has the custom pl330_reqtype enum which has the same possible settings as the generic dma_transfer_direction enum. Switching over to the generic enum internally makes it possible to directly initialize it from the transfer request direction. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-01-29Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull slave-dma updates from Vinod Koul: - new driver for BCM2835 used in R-pi - new driver for MOXA ART - dma_get_any_slave_channel API for DT based systems - minor fixes and updates spread acrooss driver [ The fsl-ssi dual fifo mode support addition clashed badly with the other changes to fsl-ssi that came in through the sound merge. I did a very rough cut at fixing up the conflict, but Nicolin Chen (author of both sides) will need to verify and check things ] * 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (36 commits) dmaengine: mmp_pdma: fix mismerge dma: pl08x: Export pl08x_filter_id acpi-dma: align documentation with kernel-doc format dma: fix vchan_cookie_complete() debug print DMA: dmatest: extend the "device" module parameter to 32 characters drivers/dma: fix error return code dma: omap: Set debug level to debugging messages dmaengine: fix kernel-doc style typos for few comments dma: tegra: add support for Tegra148/124 dma: dw: use %pad instead of casting dma_addr_t dma: dw: join split up messages dma: dw: fix style of multiline comment dmaengine: k3dma: fix sparse warnings dma: pl330: Use dma_get_slave_channel() in the of xlate callback dma: pl330: Differentiate between submitted and issued descriptors dmaengine: sirf: Add device_slave_caps interface DMA: Freescale: change BWC from 256 bytes to 1024 bytes dmaengine: Add MOXA ART DMA engine driver dmaengine: Add DMA_PRIVATE to BCM2835 driver dma: imx-sdma: Assign a default script number for ROM firmware cases ...
2014-01-20dma: pl330: Use dma_get_slave_channel() in the of xlate callbackLars-Peter Clausen
Currently the driver uses dma_request_channel() with a custom filter function to find the requested channel. This will loop over all available channels until the one we want has been found, but we already know which channel we want to request, so we can dma_get_slave_channel(). This also makes the code a bit shorter cleaner. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-01-20dma: pl330: Differentiate between submitted and issued descriptorsLars-Peter Clausen
The pl330 dmaengine driver currently does not differentiate between submitted and issued descriptors. It won't start transferring a newly submitted descriptor until issue_pending() is called, but only if it is idle. If it is active and a new descriptor is submitted before it goes idle it will happily start the newly submitted descriptor once all earlier submitted descriptors have been completed. This is not a 100% correct with regards to the dmaengine interface semantics. A descriptor is not supposed to be started until the next issue_pending() call after the descriptor has been submitted. This patch adds a second per channel list that keeps track of the submitted descriptors. Once issue_pending() is called the submitted descriptors are moved to the working list and only descriptors on the working list are started. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>