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If probe is reached, we've already matched the device and in the case of
DT matching, the struct device_node pointer will be set. Therefore, there
is no need to call of_match_device() in probe.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231006213835.332848-1-robh@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
To do so, the code needs a little shuffling related to how hw_desc is used
and nb_desc incremented.
The one by one increment is needed for the error handling path, calling
pxad_free_desc(), to work correctly.
So, add a new intermediate variable, desc, to store the result of the
dma_pool_alloc() call.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1c9ef22826f449a3756bb13a83494e9fe3e0be8b.1696676782.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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If pxad_alloc_desc() fails on the first dma_pool_alloc() call, then
sw_desc->nb_desc is zero.
In such a case pxad_free_desc() is called and it will BUG_ON().
Remove this erroneous BUG_ON().
It is also useless, because if "sw_desc->nb_desc == 0", then, on the first
iteration of the for loop, i is -1 and the loop will not be executed.
(both i and sw_desc->nb_desc are 'int')
Fixes: a57e16cf0333 ("dmaengine: pxa: add pxa dmaengine driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/c8fc5563c9593c914fde41f0f7d1489a21b45a9a.1696676782.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230919133207.1400430-34-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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platform_get_resource() and devm_ioremap_resource() are wrapped up in the
devm_platform_ioremap_resource() helper. Use the helper and get rid of the
local variable for struct resource *. We now have a function call less.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20221110152528.7821-1-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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The first IRQ is required, but IRQs 1 through (nb_phy_chans - 1) are
optional, because on some platforms (e.g. PXA168) there is a single IRQ
shared between all channels.
This change inhibits a flood of "IRQ index # not found" messages at
startup. Tested on a PXA168-based device.
Fixes: 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()")
Signed-off-by: Doug Brown <doug@schmorgal.com>
Link: https://lore.kernel.org/r/20220906000709.52705-1-doug@schmorgal.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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The generic properties, used in most of the drivers and defined in
generic dma-common DT bindings, are 'dma-channels' and 'dma-requests'.
Switch to new properties while keeping backward compatibility.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220503065407.52188-3-krzysztof.kozlowski@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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The last driver referencing the slave_id on Marvell PXA and MMP platforms
was the SPI driver, but this stopped doing so a long time ago, so the
TODO from the earlier patch can no be removed.
Fixes: b729bf34535e ("spi/pxa2xx: Don't use slave_id of dma_slave_config")
Fixes: 13b3006b8ebd ("dma: mmp_pdma: add filter function")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211122222203.4103644-7-arnd@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the struct_size() helper to do the arithmetic instead of the
argument "size + count * size" in the kzalloc() function.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
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Running in hardIRQ, disabling IRQ is redundant since hardIRQ has disabled
IRQ. This patch removes the irqsave and irqstore to save some instruction
cycles.
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Daniel Mack <daniel@zonque.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Link: https://lore.kernel.org/r/20201027215252.25820-11-song.bao.hua@hisilicon.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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Pull dmaengine updates from Vinod Koul:
- Add support in dmaengine core to do device node checks for DT devices
and update bunch of drivers to use that and remove open coding from
drivers
- New driver/driver support for new hardware, namely:
- MediaTek UART APDMA
- Freescale i.mx7ulp edma2
- Synopsys eDMA IP core version 0
- Allwinner H6 DMA
- Updates to axi-dma and support for interleaved cyclic transfers
- Greg's debugfs return value check removals on drivers
- Updates to stm32-dma, hsu, dw, pl330, tegra drivers
* tag 'dmaengine-5.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (68 commits)
dmaengine: Revert "dmaengine: fsl-edma: add i.mx7ulp edma2 version support"
dmaengine: at_xdmac: check for non-empty xfers_list before invoking callback
Documentation: dmaengine: clean up description of dmatest usage
dmaengine: tegra210-adma: remove PM_CLK dependency
dmaengine: fsl-edma: add i.mx7ulp edma2 version support
dt-bindings: dma: fsl-edma: add new i.mx7ulp-edma
dmaengine: fsl-edma-common: version check for v2 instead
dmaengine: fsl-edma-common: move dmamux register to another single function
dmaengine: fsl-edma: add drvdata for fsl-edma
dmaengine: Revert "dmaengine: fsl-edma: support little endian for edma driver"
dmaengine: rcar-dmac: Reject zero-length slave DMA requests
dmaengine: dw: Enable iDMA 32-bit on Intel Elkhart Lake
dmaengine: dw-edma: fix semicolon.cocci warnings
dmaengine: sh: usb-dmac: Use [] to denote a flexible array member
dmaengine: dmatest: timeout value of -1 should specify infinite wait
dmaengine: dw: Distinguish ->remove() between DW and iDMA 32-bit
dmaengine: fsl-edma: support little endian for edma driver
dmaengine: hsu: Revert "set HSU_CH_MTSR to memory width"
dmagengine: pl330: add code to get reset property
dt-bindings: pl330: document the optional resets property
...
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Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Also, because there is no need to save the file dentry, remove the
variable that was saving it as it was never even being used once set.
Cc: Daniel Mack <daniel@zonque.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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Pull dmaengine updates from Vinod Koul:
"This includes a new driver, removes R-Mobile APE6 as it is no longer
used, sprd cyclic dma support, last batch of dma_slave_config
direction removal and random updates to bunch of drivers.
Summary:
- New driver for UniPhier MIO DMA controller
- Remove R-Mobile APE6 support
- Sprd driver updates and support for cyclic link-list
- Remove dma_slave_config direction usage from rest of drivers
- Minor updates to dmatest, dw-dmac, zynqmp and bcm dma drivers"
* tag 'dmaengine-4.21-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (48 commits)
dmaengine: qcom_hidma: convert to DEFINE_SHOW_ATTRIBUTE
dmaengine: pxa: remove DBGFS_FUNC_DECL()
dmaengine: mic_x100_dma: convert to DEFINE_SHOW_ATTRIBUTE
dmaengine: amba-pl08x: convert to DEFINE_SHOW_ATTRIBUTE
dmaengine: Documentation: Add documentation for multi chan testing
dmaengine: dmatest: Add transfer_size parameter
dmaengine: dmatest: Add alignment parameter
dmaengine: dmatest: Use fixed point div to calculate iops
dmaengine: dmatest: Add support for multi channel testing
dmaengine: rcar-dmac: Document R8A774C0 bindings
dt-bindings: dmaengine: usb-dmac: Add binding for r8a774c0
dmaengine: zynqmp_dma: replace spin_lock_bh with spin_lock_irqsave
dmaengine: sprd: Add me as one of the module authors
dmaengine: sprd: Support DMA 2-stage transfer mode
dmaengine: sprd: Support DMA link-list cyclic callback
dmaengine: sprd: Set cur_desc as NULL when free or terminate one dma channel
dmaengine: sprd: Fix the last link-list configuration
dmaengine: sprd: Get transfer residue depending on the transfer direction
dmaengine: sprd: Remove direction usage from struct dma_slave_config
dmaengine: dmatest: fix a small memory leak in dmatest_func()
...
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We already have the DEFINE_SHOW_ATTRIBUTE, There is no need to define
such a macro, so remove DBGFS_FUNC_DECL.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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As the pxa architecture and all its related drivers do not rely anymore
on the filter function, thanks to the slave map conversion, make
pxad_filter_fn() static, and remove it from the global namespace.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Vinod Koul <vkoul@kernel.org>
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Remove unneeded semicolon.
Generated by: scripts/coccinelle/misc/semicolon.cocci
Signed-off-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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Use dmaenginem_async_device_register to simplify the code:
remove dma_async_device_unregister.
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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As what former drcmr -1 value meant, add a this as a default to each
channel, ie. that by default no requestor line is used.
This is specifically used for network drivers smc91x and smc911x, and
needed for their port to slave maps.
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Vinod Koul <vkoul@kernel.org>
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In order to remove the specific knowledge of the dma mapping from PXA
drivers, add a default slave map for pxa architectures.
This won't impact MMP architecture, but is aimed only at all PXA boards.
This is the first step, and once all drivers are converted,
pxad_filter_fn() will be made static, and the DMA resources removed from
device.c.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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
...
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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