summaryrefslogtreecommitdiff
path: root/drivers/dma
AgeCommit message (Collapse)Author
2015-11-10Merge tag 'dmaengine-4.4-rc1' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull dmaengine updates from Vinod Koul: "This time we have a very typical update which is mostly fixes and updates to drivers and no new drivers. - the biggest change is coming from Peter for edma cleanup which even caused some last minute regression, things seem settled now - idma64 and dw updates - iotdma updates - module autoload fixes for various drivers - scatter gather support for hdmac" * tag 'dmaengine-4.4-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (77 commits) dmaengine: edma: Add dummy driver skeleton for edma3-tptc Revert "ARM: DTS: am33xx: Use the new DT bindings for the eDMA3" Revert "ARM: DTS: am437x: Use the new DT bindings for the eDMA3" dmaengine: dw: some Intel devices has no memcpy support dmaengine: dw: platform: provide platform data for Intel dmaengine: dw: don't override platform data with autocfg dmaengine: hdmac: Add scatter-gathered memset support dmaengine: hdmac: factorise memset descriptor allocation dmaengine: virt-dma: Fix kernel-doc annotations ARM: DTS: am437x: Use the new DT bindings for the eDMA3 ARM: DTS: am33xx: Use the new DT bindings for the eDMA3 dmaengine: edma: New device tree binding dmaengine: Kconfig: edma: Select TI_DMA_CROSSBAR in case of ARCH_OMAP dmaengine: ti-dma-crossbar: Add support for crossbar on AM33xx/AM43xx dmaengine: edma: Merge the of parsing functions dmaengine: edma: Do not allocate memory for edma_rsv_info in case of DT boot dmaengine: edma: Refactor the dma device and channel struct initialization dmaengine: edma: Get qDMA channel information from HW also dmaengine: edma: Merge map_dmach_to_queue into assign_channel_eventq dmaengine: edma: Correct PaRAM access function names (_parm_ to _param_) ...
2015-11-04Merge tag 'char-misc-4.4-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big char/misc driver update for 4.4-rc1. Lots of different driver and subsystem updates, hwtracing being the largest with the addition of some new platforms that are now supported. Full details in the shortlog. All of these have been in linux-next for a long time with no reported issues" * tag 'char-misc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (181 commits) fpga: socfpga: Fix check of return value of devm_request_irq lkdtm: fix ACCESS_USERSPACE test mcb: Destroy IDA on module unload mcb: Do not return zero on error path in mcb_pci_probe() mei: bus: set the device name before running fixup mei: bus: use correct lock ordering mei: Fix debugfs filename in error output char: ipmi: ipmi_ssif: Replace timeval with timespec64 fpga: zynq-fpga: Fix issue with drvdata being overwritten. fpga manager: remove unnecessary null pointer checks fpga manager: ensure lifetime with of_fpga_mgr_get fpga: zynq-fpga: Change fw format to handle bin instead of bit. fpga: zynq-fpga: Fix unbalanced clock handling misc: sram: partition base address belongs to __iomem space coresight: etm3x: adding documentation for sysFS's cpu interface vme: 8-bit status/id takes 256 values, not 255 fpga manager: Adding FPGA Manager support for Xilinx Zynq 7000 ARM: zynq: dt: Updated devicetree for Zynq 7000 platform. ARM: dt: fpga: Added binding docs for Xilinx Zynq FPGA manager. ver_linux: proc/modules, limit text processing to 'sed' ...
2015-11-04Merge tag 'tty-4.4-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the big tty and serial driver update for 4.4-rc1. Lots of serial driver updates and a few small tty core changes. Full details in the shortlog. All of these have been in linux-next for a while" * tag 'tty-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (148 commits) tty: Use unbound workqueue for all input workers tty: Abstract tty buffer work tty: Prevent tty teardown during tty_write_message() tty: core: Use correct spinlock flavor in tiocspgrp() tty: Combine SIGTTOU/SIGTTIN handling serial: amba-pl011: fix incorrect integer size in pl011_fifo_to_tty() ttyFDC: Fix build problems due to use of module_{init,exit} tty: remove unneeded return statement serial: 8250_mid: add support for DMA engine handling from UART MMIO dmaengine: hsu: remove platform data dmaengine: hsu: introduce stubs for the exported functions dmaengine: hsu: make the UART driver in control of selecting this driver serial: fix mctrl helper functions serial: 8250_pci: Intel MID UART support to its own driver serial: fsl_lpuart: add earlycon support tty: disable unbind for old 74xx based serial/mpsc console port serial: pl011: Spelling s/clocks-names/clock-names/ n_tty: Remove reader wakeups for TTY_BREAK/TTY_PARITY chars tty: synclink, fix indentation serial: at91, fix rs485 properties ...
2015-11-04dmaengine: edma: Add dummy driver skeleton for edma3-tptcPeter Ujfalusi
The eDMA3 TPTC does not need any software configuration, but it is a separate IP block in the SoC. In order the omap hwmod core to be able to handle the TPTC resources correctly in regards of PM we need to have a driver loaded for it. This patch will add a dummy driver skeleton without probe or remove callbacks provided. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Reported-by: Olof Johansson <olof@lixom.net> Tested-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-31Merge branch 'topic/ioatdma' into for-linusVinod Koul
2015-10-31Merge branch 'topic/idma' into for-linusVinod Koul
2015-10-31Merge branch 'topic/edma' into for-linusVinod Koul
Signed-off-by: Vinod Koul <vinod.koul@intel.com> Conflicts: drivers/dma/edma.c
2015-10-31Merge branch 'topic/dw' into for-linusVinod Koul
2015-10-31dmaengine: dw: some Intel devices has no memcpy supportAndy Shevchenko
Provide a flag to choose if the device does support memory-to-memory transfers. At least this is not true for iDMA32 controller that might be supported in the future. Besides that Intel BayTrail and Braswell users should not try this feature due to HW specific behaviour. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-31dmaengine: dw: platform: provide platform data for IntelAndy Shevchenko
Provide platform data explicitly for Intel SoCs where dw_dmac is enumerated by ACPI. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-31dmaengine: dw: don't override platform data with autocfgAndy Shevchenko
Let probe driver decide either it wants to auto configure the driver or have explicitly defined properties. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-29dmaengine: hdmac: Add scatter-gathered memset supportMaxime Ripard
Just like memset support, the HDMAC might be used to do a memset over a discontiguous memory area. In such a case, we'll just build up a chain of memset descriptors over the contiguous chunks of memory to set, in order to allow such a support. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-29dmaengine: hdmac: factorise memset descriptor allocationMaxime Ripard
The memset and scatter gathered memset are going to use some common logic to create their descriptors. Move that logic into a function of its own so that we can share it with the future memset_sg callback. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-29Merge branch 'topic/dw' into for-linusVinod Koul
2015-10-27dmaengine: virt-dma: Fix kernel-doc annotationsLars-Peter Clausen
In kernel-doc annotations parameters need to start with a @ for them to be properly recognized. Add those where missing for virt-dma. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: New device tree bindingPeter Ujfalusi
With the old binding and driver architecture we had many issues: No way to assign eDMA channels to event queues, thus not able to tune the system by moving specific DMA channels to low/high priority servicing. We moved the cyclic channels to high priority within the code, but that was just a workaround to this issue. Memcopy was fundamentally broken: even if the driver scanned the DT/devices in the booted system for direct DMA users (which is not effective when the events are going through a crossbar) and created a map of 'used' channels, this information was not really usable. Since via dmaengien API the eDMA driver will be called with _some_ channel number, we would try to request this channel when any channel is requested for memcpy. By luck we got channel which is not used by any device most of the time so things worked, but if a device would have been using the given channel, but not requested it, the memcpy channel would have been waiting for HW event. The old code had the am33xx/am43xx DMA event router handling embedded. This should have been done in a separate driver since it is not part of the actual eDMA IP. There were no way to 'lock' PaRAM slots to be used by the DSP for example when booting with DT. In DT boot the edma node used more than one hwmod which is not a good practice and the kernel prints warning because of this. With the new bindings and the changes in the driver we can: - No regression with Legacy binding and non DT boot - DMA channels can be assigned to any TC (to set priority) - PaRAM slots can be reserved for other cores to use - Dynamic power management for CC and TCs, if only TC0 is used all other TC can be powered down for example Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: Kconfig: edma: Select TI_DMA_CROSSBAR in case of ARCH_OMAPPeter Ujfalusi
Since the crossbar is needed for eDMA when it is used on OMAP like platforms (am335x/am437x and later DRA7xx), select the crossbar to be built if ARCH_OMAP is set. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: ti-dma-crossbar: Add support for crossbar on AM33xx/AM43xxPeter Ujfalusi
The DMA event crossbar on AM33xx/AM43xx is different from the one found in DRA7x family. Instead of a single event crossbar it has 64 identical mux attached to each eDMA event line. When the 0 event mux is selected, the default mapped event is going to be routed to the corresponding eDMA event line. If different mux is selected, then the selected event is going to be routed to the given eDMA event. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Merge the of parsing functionsPeter Ujfalusi
Instead of nesting functions just merge them since the resulting function is still small and readable. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Do not allocate memory for edma_rsv_info in case of DT bootPeter Ujfalusi
The channel/slot reservation is not supported when booted with DT so there is not need to allocate memory. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Refactor the dma device and channel struct initializationPeter Ujfalusi
Move all code under one function to do the dma device and eDMA channel related setup so they are not scattered around the driver. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Get qDMA channel information from HW alsoPeter Ujfalusi
Query the number of qDMA channels from CCCFG register. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Merge map_dmach_to_queue into assign_channel_eventqPeter Ujfalusi
edma_assign_channel_eventq() is a wrapper around edma_map_dmach_to_queue() We can merge the content of the later so we will have only one function to be used for mapping channels to given eventq Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Correct PaRAM access function names (_parm_ to _param_)Peter Ujfalusi
These inline functions are designed to modify parts of the PaRAM in eDMA. Change the names accordingly. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Simplify function parameter list for channel operationsPeter Ujfalusi
Instead of passing a pointer to struct edma_cc and the channel number, pass only the pointer to the edma_chan structure for the given channel. This struct contains all the information needed by the functions and the use of this makes it obvious that most of the sanity checks can be removed from the driver. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Optimize memcpy operationPeter Ujfalusi
If the transfer is shorted then 64K we can complete it with one ACNT burst by configuring ACNT to the length of the copy, this require one paRAM slot. Otherwise we use two paRAM slots for the copy: slot1: will copy (length / 32767) number of 32767 byte long blocks slot2: will be configured to copy the remaining data. According to tests this patch increases the throughput of memcpy from ~3MB/s to 15MB/s Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-27dmaengine: edma: Remove alignment constraint for memcpyPeter Ujfalusi
Despite the claim by the original commit adding the memcpy support, eDMA does not have constraint on the alignment of src, dst or length in increment mode. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-25Merge branch 'device-properties'Rafael J. Wysocki
* device-properties: ACPI / property: Fix subnode lookup scope for data-only subnodes acpi-dma: Add support for "dma-names" device property device property: Add fwnode_property_match_string() ACPI / property: Extend device_get_next_child_node() to data-only nodes ACPI / gpio: Split acpi_get_gpiod_by_index() ACPI / property: Extend fwnode_property_* to data-only subnodes ACPI / property: Expose data-only subnodes via sysfs ACPI / property: Add support for data-only subnodes ACPI / property: Add routine for extraction of _DSD properties
2015-10-25dmaengine: ste_dma40: fix a trivial typoGeliang Tang
s/regsiter/register/ Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-17dmaengine: hsu: remove platform dataHeikki Krogerus
There are no platforms where it's not possible to calculate the number of channels based on IO space length, and since that is the only purpose for struct hsu_dma_platform_data, removing it. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Vinod Koul <vinod.koul@intel.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17dmaengine: hsu: make the UART driver in control of selecting this driverHeikki Krogerus
HSU (High Speed UART) DMA engine, like the name suggests, is an integrated DMA engine for UART and UART alone. Therefore, making the UART drivers responsible of selecting it and removing the user selectable option for it. The UARTs with this DMA engine can always select HSU_DMA when SERIAL_8250_DMA option is enabled. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Vinod Koul <vinod.koul@intel.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-14dmaengine: xgene-dma: Remove memcpy offload support due to performance dropRameshwar Prasad Sahu
The DMA engine supports memory copy, RAID5 XOR, RAID6 PQ, and other computations. But the bandwidth of the entire DMA engine is shared among all channels. This patch re-configures operations availability such that one can achieve maximum performance for XOR and PQ computation by removing the memory offload operations. Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Dynamic paRAM slot handling if HW supports itPeter Ujfalusi
If the eDMA3 has support for channel paRAM slot mapping we can utilize it to allocate slots on demand and save precious slots for real transfers. On am335x the eDMA has 64 channels which means we can unlock 64 paRAM slots out from the available 256. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Rename bitfields for slot and channel usage trackingPeter Ujfalusi
The names chosen for the bitfields were quite confusing and given no real information on what they are used for... edma_inuse -> slot_inuse: tracks the slot usage/availability edma_unused -> channel_unused: tracks the channel usage/availability Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Read channel mapping support only once from HWPeter Ujfalusi
Instead of directly reading it from CCCFG register take the information out once when we set up the configuration from the HW. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Simplify and optimize ccerr interrupt handlerPeter Ujfalusi
No need to run through the bits in QEMR and CCERR events since they will not trigger any action, so just clearing the errors there is fine. In case of the missed event the loop can be optimized so we spend less time to handle the event. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Move the pending error check into helper functionPeter Ujfalusi
In the ccerr interrupt handler the code checks for pending errors in the error status registers in two different places. Move the check out to a helper function. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Simplify the interrupt handlingPeter Ujfalusi
With the merger of the arch/arm/common/edma.c code into the dmaengine driver, there is no longer need to have per channel callback/data storage for interrupt events. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Consolidate the comments for functionsPeter Ujfalusi
Remove or rewrite the comments for the internal functions. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Print warning when linking slots from different eDMAPeter Ujfalusi
Warning message in case of linking between paRAM slots in different eDMA controllers. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Use the edma_write_slot instead open coded memcpy_toioPeter Ujfalusi
edma_write_slot() is for writing an entire paRAM slot. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Use dev_dbg instead pr_debugPeter Ujfalusi
We have access to dev, so it is better to use the dev_dbg for debug prints. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Cleanup regarding the use of dev around the codePeter Ujfalusi
Be consistent and do not mix the use of dev, &pdev->dev, etc in the functions. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Use devm_kcalloc when possiblePeter Ujfalusi
When allocating a memory for number of items it is better (looks better) to use devm_kcalloc. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Allocate memory dynamically for bitmaps and structuresPeter Ujfalusi
Instead of using defines to specify the size of different arrays and bitmaps, allocate the memory for them based on the information we get from the HW itself. Since these defines are set based on the worst case, there are devices where they are not valid. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14ARM/dmaengine: edma: Merge the two drivers under drivers/dma/Peter Ujfalusi
Move the code out from arch/arm/common and merge it inside of the dmaengine driver. This change is done with as minimal (if eny) functional change to the code as possible to avoid introducing regression. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14ARM/dmaengine: edma: Remove limitation on the number of eDMA controllersPeter Ujfalusi
Since the driver stack no longer depends on lookup with id number in a global array of pointers, the limitation for the number of eDMAs are no longer needed. We can handle as many eDMAs in legacy and DT boot as we have memory for them to allocate the needed structures. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14ARM/dmaengine: edma: Public API to use private struct pointerPeter Ujfalusi
Instead of relying on indexes pointing to edma private date in the global pointer array, pass the private data pointer via the public API. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14ARM/dmaengine: edma: Move of_dma_controller_register to the dmaengine driverPeter Ujfalusi
If the of_dma_controller is registered in the non dmaengine driver we could have race condition: the of_dma_controller has been registered, but the dmaengine driver is not yet probed. Drivers requesting DMA channels during this window will fail since we do not yet have dmaengine drivers registered. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-14dmaengine: edma: Simplify and optimize the edma_execute pathPeter Ujfalusi
The code path in edma_execute() and edma_callback() can be simplified and make it more optimal. There is not need to call in to edma_execute() when the transfer has been finished for example. Also the handling of missed/first or next batch of paRAMs can be done in a more optimal way. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>