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path: root/drivers/dma/pxa_dma.c
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2016-10-18Revert "dmaengine: pxa_dma: add support for legacy transition"Robert Jarzmik
This reverts commit c91134d9194478144ba579ca6efeddf628055650. The conversion of the pxa architecture is now finished for all drivers, so this functions has fullfilled its purpose and can now be removed. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-08-19dmaengine: pxa_dma: fix debug messageRobert Jarzmik
In a very tight timeframe, the debug message in the transfer completion handler can be misleading, as the completion test report can change just after the message, and the code flow cannot be deduced from the debug message. This is just a cleanup to make debugging easier. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-08-19dmaengine: pxa_dma: fix hotchain corner caseRobert Jarzmik
In the case where a descriptor is chained on a running channel, and as explained in the comment in the code 10 lines above, the success of the chaining is ensured either if : - the DMA is still running - or if the chained transfer is completed Unfortunately the transfer completness test was done on the descriptor to which the transfer was chained, and not the transfer being chained at the end, ie. hot-chained. This corner case is extremely hard to trigger, as usually the DMA chain is still running, and the first case takes care of returning success of the hot-chaining. It was seen by hot-chaining several "small transfers" to a running "big transfer", not in a real-life usecase but by testing the robustness of the driver. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-07-23dmaengine: pxa_dma: implement device_synchronizeRobert Jarzmik
Implement the function which wait until a dma channel is stopped to have a synchronization point. This also protects the pxad_remove() from races, such as spurious interrupts while removing the driver, because : - as long as there is one dma channel requested, ie. dma_chan_get() but no dma_chan_put(), the try_module_get() of dma_chan_get() prevents the remove() routine from running - when the last channel is released, ie. the last dma_chan_put() is called, if there is a running DMA, pxad_synchronize() is called - pxad_synchronize() waits for the channel to stop, which in turn ensures on pxa architecture that the interrupt cannot be fired anymore Reported-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-07-23dmaengine: pxa_dma: remove owner assignmentVinod Koul
debugfs file operations owner is set by core, so remove Signed-off-by: Vinod Koul <vinod.koul@intel.com> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
2016-04-26dmaengine: pxa_dma: remove duplicate const qualifierEric Engestrom
Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-04-26dmaengine: pxa: handle bus errorsRobert Jarzmik
In the current state, upon bus error the driver will spin endlessly, relaunching the last tx, which will fail again and again : - a bus error happens - pxad_chan_handler() is called - as PXA_DCSR_STOPSTATE is true, the last non-terminated transaction is lauched, which is the one triggering the bus error, as it didn't terminate - moreover, the STOP interrupt fires a new, as the STOPIRQEN is still active Break this logic by stopping the automatic relaunch of a dma channel upon a bus error, even if there are still pending issued requests on it. As dma_cookie_status() seems unable to return DMA_ERROR in its current form, ie. there seems no way to mark a DMA_ERROR on a per-async-tx basis, it is chosen in this patch to remember on the channel which transaction failed, and report it in pxad_tx_status(). It's a bit misleading because if T1, T2, T3 and T4 were queued, and T1 was completed while T2 causes a bus error, the status of T3 and T4 will be reported as DMA_IN_PROGRESS, while the channel is actually stopped. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-03-20Merge tag 'armsoc-soc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC platform updates from Arnd Bergmann: "Newly added support for additional SoCs: - Axis Artpec-6 SoC family - Allwinner A83T SoC - Mediatek MT7623 - NXP i.MX6QP SoC - ST Microelectronics stm32f469 microcontroller New features: - SMP support for Mediatek mt2701 - Big-endian support for NXP i.MX - DaVinci now uses the new DMA engine dma_slave_map - OMAP now uses the new DMA engine dma_slave_map - earlyprintk support for palmchip uart on mach-tango - delay timer support for orion Other: - Exynos PMU driver moved out to drivers/soc/ - Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP, uniphier" * tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (83 commits) ARM: uniphier: rework SMP code to support new System Bus binding ARM: uniphier: add missing of_node_put() ARM: at91: avoid defining CONFIG_* symbols in source code ARM: DRA7: hwmod: Add data for eDMA tpcc, tptc0, tptc1 ARM: imx: Make reset_control_ops const ARM: imx: Do L2 errata only if the L2 cache isn't enabled ARM: imx: select ARM_CPU_SUSPEND only for imx6 dmaengine: pxa_dma: fix the maximum requestor line ARM: alpine: select the Alpine MSI controller driver ARM: pxa: add the number of DMA requestor lines dmaengine: mmp-pdma: add number of requestors dma: mmp_pdma: Add the #dma-requests DT property documentation ARM: OMAP2+: Add rtc hwmod configuration for ti81xx ARM: s3c24xx: Avoid warning for inb/outb ARM: zynq: Move early printk virtual address to vmalloc area ARM: DRA7: hwmod: Add custom reset handler for PCIeSS ARM: SAMSUNG: Remove unused register offset definition ARM: EXYNOS: Cleanup header files inclusion drivers: soc: samsung: Enable COMPILE_TEST MAINTAINERS: Add maintainers entry for drivers/soc/samsung ...
2016-03-03dmaengine: pxa_dma: fix cyclic transfersRobert Jarzmik
While testing audio with pxa2xx-ac97, underrun were happening while the user application was correctly feeding the music. Debug proved that the cyclic transfer is not cyclic, ie. the last descriptor did not loop on the first. Another issue is that the descriptor length was always set to 8192, because of an trivial operator issue. This was tested on a pxa27x platform. Fixes: a57e16cf0333 ("dmaengine: pxa: add pxa dmaengine driver") Reported-by: Vasily Khoruzhick <anarsoul@gmail.com> Tested-by: Vasily Khoruzhick <anarsoul@gmail.com> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-02-26dmaengine: pxa_dma: fix the maximum requestor lineRobert Jarzmik
The current number of requestor lines is limited to 31. This was an error of a previous commit, as this number is platform dependent, and is actually : - for pxa25x: 40 requestor lines - for pxa27x: 75 requestor lines - for pxa3xx: 100 requestor lines The previous testing did not reveal the faulty constant as on pxa[23]xx platforms, only camera, MSL and USB are above requestor 32, and in these only the camera has a driver using dma. Fixes: e87ffbdf0697 ("dmaengine: pxa_dma: fix the no-requestor case") Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Acked-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16dmaengine: pxa_dma: declare transfer are reusableRobert Jarzmik
As this driver provides a mechanism to reuse transfers, declare it in its probe function. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-01dmaengine: pxa_dma: fix residue corner caseRobert Jarzmik
A very tiny temporal window exists in the residue calculation where : - upon entering residue calculation, the transfer is ongoing - when reading the current transfer pointer, it just changed to the "finisher/linker" descriptor In this case, the residue returned is the whole transfer length instead of 0. Fix it. This appears almost in one extreme case, where the driver is used by older clients which inquire for residue in interrupt context, such as the smsc91x ethernet driver, in a tight loop : interrupt_handler() dmaengine_submit() do { dmaengine_tx_status() } while (residue > 0 || status != DMA_ERROR) Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-01dmaengine: pxa_dma: fix the no-requestor caseRobert Jarzmik
A very small number of devices don't use the flow control offered by requestor lines. In these specific cases, the pxa dma driver should be aware of that and not try to use a requestor line. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-09-25dmaengine: pxa_dma: fix initial list moveRobert Jarzmik
Since the commit to have an allocated list of virtual descriptors was reverted, the pxa_dma driver is broken, as it assumes the descriptor is placed on the allocated list upon allocation. Fix the issue in pxa_dma by making an allocated virtual descriptor a singleton. Fixes: 8c8fe97b2b8a ("Revert "dmaengine: virt-dma: don't always free descriptor upon completion"") Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-18dmaengine: pxa_dma: fix debug informationRobert Jarzmik
This fixes the following error: drivers/dma/pxa_dma.c: In function ‘dbg_show_requester_chan’: drivers/dma/pxa_dma.c:192:2: error: void value not ignored as it ought to be pos += seq_printf(s, "DMA channel %d requester :\n", phy->idx); ^ drivers/dma/pxa_dma.c:197:8: error: void value not ignored as it ought to be !!(drcmr & DRCMR_MAPVLD)); ^ scripts/Makefile.build:258: recipe for target 'drivers/dma/pxa_dma.o' failed Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-17dmaengine: pxa_dma: don't use config direction parameterRobert Jarzmik
Don't use the direction passed in the configuration, and rely on each transfer's direction to prepare the transfers. This will enable future removal of direction parameter from dma_slave_config. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-29dmaengine: pxa_dma: add support for legacy transitionRobert Jarzmik
In order to achieve smooth transition of pxa drivers from old legacy dma handling to new dmaengine, introduce a function to "hide" dma physical channels from dmaengine. This is temporary situation where pxa dma will be handled in 2 places : - arch/arm/plat-pxa/dma.c - drivers/dma/pxa_dma.c The resources, ie. dma channels, will be controlled by pxa_dma. The legacy code will request or release a channel with pxad_toggle_reserved_channel(). This is not very pretty, but it ensures both legacy and dmaengine consumers can live in the same kernel until the conversion is done. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-26dmaengine: pxa_dma: add debug informationRobert Jarzmik
Reuse the debugging features which were available in pxa architecture. This is a copy of the code from arch/arm/plat-pxa/dma, which is doomed to disappear once the conversion is completed towards dmaengine. This is a transfer of the commit "[ARM] pxa/dma: add debugfs entries" (d294948c2ce4e1c85f452154469752cc9b8e876d). Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-26dmaengine: pxa: add pxa dmaengine driverRobert Jarzmik
This is a new driver for pxa SoCs, which is also compatible with the former mmp_pdma. The rationale behind a new driver (as opposed to incremental patching) was : - the new driver relies on virt-dma, which obsoletes all the internal structures of mmp_pdma (sw_desc, hw_desc, ...), and by consequence all the functions - mmp_pdma allocates dma coherent descriptors containing not only hardware descriptors but linked list information The new driver only puts the dma hardware descriptors (ie. 4 u32) into the dma pool allocated memory. This changes completely the way descriptors are handled - the architecture behind the interrupt/tasklet management was rewritten to be more conforming to virt-dma - the buffers alignment is handled differently The former driver assumed that the DMA channel stopped between each descriptor. The new one chains descriptors to let the channel running. This is a necessary guarantee for real-time high bandwidth usecases such as video capture on "old" architectures such as pxa. - hot chaining / cold chaining / no chaining Whenever possible, submitting a descriptor "hot chains" it to a running channel. There is still no guarantee that the descriptor will be issued, as the channel might be stopped just before the descriptor is submitted. Yet this allows to submit several video buffers, and resubmit a buffer while another is under handling. As before, dma_async_issue_pending() is the only guarantee to have all the buffers issued. When an alignment issue is detected (ie. one address in a descriptor is not a multiple of 8), if the already running channel is in "aligned mode", the channel will stop, and restarted in "misaligned mode" to finished the issued list. - descriptors reusing A submitted, issued and completed descriptor can be reused, ie resubmitted if it was prepared with the proper flag (DMA_PREP_ACK). Only a channel resources release will in this case release that buffer. This allows a rolling ring of buffers to be reused, where there are several thousands of hardware descriptors used (video buffer for example). Additionally, a set of more casual features is introduced : - debugging traces - lockless way to know if a descriptor is terminated or not The driver was tested on zylonite board (pxa3xx) and mioa701 (pxa27x), with dmatest, pxa_camera and pxamci. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>