Commit Graph

560570 Commits

Author SHA1 Message Date
Vinod Koul
c8b9dd2b9e Merge branch 'topic/stm32' into for-linus 2016-01-06 15:18:56 +05:30
Vinod Koul
62ddae372f Merge branch 'topic/ste' into for-linus 2016-01-06 15:18:44 +05:30
Vinod Koul
a6eaf23b05 Merge branch 'topic/rcar' into for-linus 2016-01-06 15:18:36 +05:30
Vinod Koul
c81bc96056 Merge branch 'topic/omap' into for-linus 2016-01-06 15:18:19 +05:30
Vinod Koul
e3c373616a Merge branch 'topic/ioatdma' into for-linus 2016-01-06 15:18:11 +05:30
Vinod Koul
9fd5ca5f04 Merge branch 'topic/idma' into for-linus 2016-01-06 15:18:05 +05:30
Vinod Koul
d3f1e93ce8 Merge branch 'topic/async' into for-linus 2016-01-06 15:17:47 +05:30
Vinod Koul
7c7b680fa6 Merge branch 'topic/univ_api' into for-linus 2016-01-06 15:17:32 +05:30
Vinod Koul
5eec94388d Merge branch 'topic/desc_reuse' into for-linus 2016-01-06 15:17:16 +05:30
Peter Ujfalusi
020c62ae38 dmaengine: omap-dma: Add support for DMA filter mapping to slave devices
Add support for providing device to filter_fn mapping so client drivers
can switch to use the dma_request_chan() API.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:17:26 +05:30
Peter Ujfalusi
23e6723c06 dmaengine: edma: Add support for DMA filter mapping to slave devices
Add support for providing device to filter_fn mapping so client drivers
can switch to use the dma_request_chan() API.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:17:26 +05:30
Peter Ujfalusi
a8135d0d79 dmaengine: core: Introduce new, universal API to request a channel
The two API function can cover most, if not all current APIs used to
request a channel. With minimal effort dmaengine drivers, platforms and
dmaengine user drivers can be converted to use the two function.

struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask);

To request any channel matching with the requested capabilities, can be
used to request channel for memcpy, memset, xor, etc where no hardware
synchronization is needed.

struct dma_chan *dma_request_chan(struct device *dev, const char *name);
To request a slave channel. The dma_request_chan() will try to find the
channel via DT, ACPI or in case if the kernel booted in non DT/ACPI mode
it will use a filter lookup table and retrieves the needed information from
the dma_slave_map provided by the DMA drivers.
This legacy mode needs changes in platform code, in dmaengine drivers and
finally the dmaengine user drivers can be converted:

For each dmaengine driver an array of DMA device, slave and the parameter
for the filter function needs to be added:

static const struct dma_slave_map da830_edma_map[] = {
	{ "davinci-mcasp.0", "rx", EDMA_FILTER_PARAM(0, 0) },
	{ "davinci-mcasp.0", "tx", EDMA_FILTER_PARAM(0, 1) },
	{ "davinci-mcasp.1", "rx", EDMA_FILTER_PARAM(0, 2) },
	{ "davinci-mcasp.1", "tx", EDMA_FILTER_PARAM(0, 3) },
	{ "davinci-mcasp.2", "rx", EDMA_FILTER_PARAM(0, 4) },
	{ "davinci-mcasp.2", "tx", EDMA_FILTER_PARAM(0, 5) },
	{ "spi_davinci.0", "rx", EDMA_FILTER_PARAM(0, 14) },
	{ "spi_davinci.0", "tx", EDMA_FILTER_PARAM(0, 15) },
	{ "da830-mmc.0", "rx", EDMA_FILTER_PARAM(0, 16) },
	{ "da830-mmc.0", "tx", EDMA_FILTER_PARAM(0, 17) },
	{ "spi_davinci.1", "rx", EDMA_FILTER_PARAM(0, 18) },
	{ "spi_davinci.1", "tx", EDMA_FILTER_PARAM(0, 19) },
};

This information is going to be needed by the dmaengine driver, so
modification to the platform_data is needed, and the driver map should be
added to the pdata of the DMA driver:

da8xx_edma0_pdata.slave_map = da830_edma_map;
da8xx_edma0_pdata.slavecnt = ARRAY_SIZE(da830_edma_map);

The DMA driver then needs to configure the needed device -> filter_fn
mapping before it registers with dma_async_device_register() :

ecc->dma_slave.filter_map.map = info->slave_map;
ecc->dma_slave.filter_map.mapcnt = info->slavecnt;
ecc->dma_slave.filter_map.fn = edma_filter_fn;

When neither DT or ACPI lookup is available the dma_request_chan() will
try to match the requester's device name with the filter_map's list of
device names, when a match found it will use the information from the
dma_slave_map to get the channel with the dma_get_channel() internal
function.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:17:26 +05:30
Peter Ujfalusi
7bd903c5ca dmaengine: core: Move and merge the code paths using private_candidate
Channel matching with private_candidate() is used in two paths, the error
checking is slightly different in them and they are duplicating code also.
Move the code under find_candidate() to provide consistent execution and
going to allow us to reuse this mode of channel lookup later.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:17:26 +05:30
Peter Ujfalusi
26b64256e0 dmaengine: core: Skip mask matching when it is not provided to private_candidate
If mask is NULL skip the mask matching against the DMA device capabilities.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:17:26 +05:30
Damien.Horsley
0c328de771 dmaengine: mdc: Correct terminate_all handling
Use of the CANCEL bit in mdc_terminate_all creates an
additional 'command done' to appear in the registers (in
addition to an interrupt).

In addition, there is a potential race between
mdc_terminate_all and the irq handler if a transfer
completes at the same time as the terminate all (presently
this results in an inappropriate warning).

To handle these issues, any outstanding 'command done'
events are cleared during mdc_terminate_all and the irq
handler takes no action when there are no new 'command done'
events.

Signed-off-by: Damien.Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:12:29 +05:30
Peter Ujfalusi
4fa2d09c1a dmaengine: edma: Add probe callback to edma_tptc_driver
Due to changes in device and platform code drivers w/o probe will fail to
load. This means that the devices for eDMA TPTCs are goign to be without
driver and omap hwmod code will turn them off after the kernel finished
loading:
[    3.015900] platform 49800000.tptc: omap_device_late_idle: enabled but no driver.  Idling
[    3.024671] platform 49a00000.tptc: omap_device_late_idle: enabled but no driver.  Idling

This will prevent eDMA to work since the TPTCs are not enabled.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Fixes: 34635b1acc ("dmaengine: edma: Add dummy driver skeleton for edma3-tptc")
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:03:11 +05:30
Mans Rullgard
2b574ba9c5 dmaengine: dw: fix potential memory leak in dw_dma_parse_dt()
If the "dma-channels" DT property is missing, the dw_dma_parse_dt()
function return NULL, but not before allocating memory for a struct
dw_dma_platform_data through devres.  If the device supports parameter
detection, the probe still succeeds and the allocated memory is not
released until the device is removed.

Fix this by deferring the allocation until after checking the
"dma-channels" property.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 10:59:32 +05:30
M'boumba Cedric Madianga
aea08a5dfa dmaengine: stm32-dma: Fix unchecked deference of chan->desc
'commit d8b468394f ("dmaengine: Add STM32 DMA driver")' leads to the
following Smatch complaint:

drivers/dma/stm32-dma.c:562 stm32_dma_issue_pending()
    error: we previously assumed 'chan->desc' could be null (see line 560)

So, this patch fixes the unchecked dereference of chan->desc by returning
operation not permitted error when stm32_dma_start_transfer() does not
succeed to allocate a virtual channel descriptor.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-10 09:45:22 +05:30
Geert Uytterhoeven
4d42e95fc7 dmaengine: sh: Remove unused R-Car HPB-DMAC driver
As of commit 4baadb9e05 ("ARM: shmobile: r8a7778: remove obsolete
setup code"), the Renesas R-Car HPB-DMAC driver is no longer used.
In theory it could still be used on R-Car Gen1 SoCs, but that requires
adding DT support to the driver, which is not planned.

Remove the driver, it can be resurrected from git history when needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-10 09:43:33 +05:30
Simon Horman
0b2eed4987 dmaengine: usb-dmac: Document SoC specific compatibility strings
In general Renesas hardware is not documented to the extent where the
relationship between IP blocks on different SoCs can be assumed although
they may appear to operate the same way. Furthermore the documentation
typically does not specify a version for individual IP blocks. For these
reasons a convention of using the SoC name in place of a version and
providing SoC-specific compatibility strings has been adopted.

Although not universally liked this convention is used in the bindings for
most drivers for Renesas hardware. The purpose of this patch is to
update the Renesas USB DMA Controller driver to follow this convention.

Cc: devicetree@vger.kernel.org
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-10 09:43:11 +05:30
Markus Elfring
aeb8974ac7 ste_dma40: Delete an unnecessary variable initialisation in d40_probe()
The variable "res" will eventually be set to a resource pointer from
a call of the d40_hw_detect_init(() function.
Thus let us omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-10 09:17:10 +05:30
Markus Elfring
a9bae06dd0 ste_dma40: Delete another unnecessary check in d40_probe()
A single jump label was used by the d40_probe() function in several cases
for error handling which was a bit inefficient here.

* This implementation detail could be improved by the introduction
  of another jump label.

* Remove an extra check for the variable "base".

* Omit its explicit initialisation at the beginning then.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-10 09:17:05 +05:30
Markus Elfring
e0f8c58003 ste_dma40: Delete an unnecessary check before the function call "kmem_cache_destroy"
The kmem_cache_destroy() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-10 09:16:48 +05:30
Lars-Peter Clausen
9ff68186ea dmaengine: img-mdc: Remove unnecessary synchronize_irq() before devm_free_irq()
Calling synchronize_irq() right before devm_free_irq() is quite useless. On
one hand the IRQ can easily fire again before devm_free_irq() is entered,
on the other hand devm_free_irq() itself calls synchronize_irq() internally
(in a race condition free way), before any state associated with the IRQ is
freed.

Patch was generated using the following semantic patch:
// <smpl>
@@
expression irq, dev;
@@
-synchronize_irq(irq);
 devm_free_irq(dev, irq, ...);
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 15:56:42 +05:30
Lars-Peter Clausen
1f281792f6 dmaengine: at_xdmac: Remove unnecessary synchronize_irq() before free_irq()
Calling synchronize_irq() right before free_irq() is quite useless. On one
hand the IRQ can easily fire again before free_irq() is entered, on the
other hand free_irq() itself calls synchronize_irq() internally (in a race
condition free way), before any state associated with the IRQ is freed.

Patch was generated using the following semantic patch:
// <smpl>
@@
expression irq;
@@
-synchronize_irq(irq);
 free_irq(irq, ...);
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 15:56:27 +05:30
Yuan Yao
82d149b86d dmaengine: fsl-edma: add PM suspend/resume support
This add power management suspend/resume support for the fsl-edma
driver.

eDMA acted as a basic function used by others. What it needs to do
is the two steps below to support power management.

In fsl_edma_suspend_late:
Check whether the DMA chan is idle, if it is not idle disable DMA
request.

In fsl_edma_resume_early:
Enable the eDMA and wait for being used.

Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 15:52:13 +05:30
Andy Shevchenko
f0579c8cea dmaengine: hsu: speed up residue calculation
There is no need to calculate an overall length of the descriptor each time we
call for DMA transfer status. Instead we do this at descriptor allocation stage
and keep the stored length for further usage.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 14:00:34 +05:30
Andy Shevchenko
f94cf9f4c5 dmaengine: acpi-dma: check for 64-bit MMIO address
Currently the match DMA controller is done only for lower 32 bits of
address which might be not true on 64-bit platform. Check upper portion
as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 14:00:34 +05:30
Andy Shevchenko
390c49f717 dmaengine: idma64: use local variable to index descriptor
Since a local variable contains the number of hardware desriptors at the
beginning of idma64_desc_fill() we may use it to index the last descriptor as
well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:54:28 +05:30
Andy Shevchenko
ac02979413 dmaengine: idma64: convert idma64_hw_desc_fill() to return void
Explicitly show in idma64_desc_fill() how we link the hardware
descriptors.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:54:28 +05:30
Andy Shevchenko
e3fdb1894c dmaengine: idma64: set maximum allowed segment size for DMA
This tells, for example, IOMMU what the maximum size of a segment
the DMA controller can send.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:54:28 +05:30
Andy Shevchenko
37580559f3 dmaengine: idma64: drop IRQ enable / disable in handler
There is no need to disable interrupts in the IRQ handler. The driver
guarantess that at one time only one descriptor is active, besides the fact
that each call to the same channel will be serialized in idma64_chan_irq()
handler anyway.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:54:28 +05:30
Ludovic Desroches
95da0c19d1 dmaengine: at_xdmac: fix spurious flag status for mem2mem transfers
When setting the channel configuration register, the perid field is not
set to 0 since it is useless for mem2mem transfers. Unfortunately, a
device has 0 as perid. It could cause spurious flags status because
the controller could mix some events from the two channels.
For that reason, use the highest perid value for mem2mem transfers since it
doesn't match the perid of other devices.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:47:37 +05:30
Lars-Peter Clausen
b1d6ab1aa8 dmaengine: Add might_sleep() to dmaengine_synchronize()
Implementations of dmaengine_synchronize() are allowed to sleep, hence the
function must not be called to from atomic context. Add might_sleep() to
dmaengine_synchronize() to make it easier to detect non-compliant callers.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:43:30 +05:30
Yoshihiro Shimoda
d9f5efade2 dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all()
This patch fixes an issue that list_for_each_entry() in
usb_dmac_chan_terminate_all() is possible to cause endless loop because
this will move own desc to the desc_freed. So, this driver should use
list_for_each_entry_safe() instead of list_for_each_entry().

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:37:51 +05:30
Peter Ujfalusi
1a7cf7b26f dmaengine: omap-dma: Handle cases when the channel is polled for completion
When a DMA client driver decides that it is not providing callback for
completion of a transfer (and/or does not set the DMA_PREP_INTERRUPT) but
it will poll the status of the transfer (in case of short memcpy for
example) we will not get interrupt for the completion of the transfer and
will not mark the transaction as done.
Check the channel enable bit in the CCR when the status is queried and if
the channel is no longer active, we call the omap_dma_callback() to handle
the transfer completion.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:36:38 +05:30
Peter Ujfalusi
1c1d25f9f9 dmaengine: omap-dma: Remove tasklet to start the transfers
The use of tasklet to actually start the DMA transfer slightly decreases the
DMA throughput since it adds small scheduling delay when the transfer is
started. In normal use, even with high I/O load the tasklet would start
one transaction at a time, however running the DMAtest for memcpy on all
available channels will cause the tasklet to start about 15 transfers.
The performance numbers on OMAP4 PandaBoard-es (test_buf_size = 6553):
With the tasklet:
dmatest: dma0chan30-copy: summary 5000 tests, 0 failures 186 iops 593 KB/s (0)
dmatest: dma0chan8-copy0: summary 5000 tests, 0 failures 184 iops 584 KB/s (0)
dmatest: dma0chan13-copy: summary 5000 tests, 0 failures 184 iops 585 KB/s (0)
dmatest: dma0chan12-copy: summary 5000 tests, 0 failures 184 iops 585 KB/s (0)
dmatest: dma0chan7-copy0: summary 5000 tests, 0 failures 183 iops 581 KB/s (0)

With this patch (no tasklet):
dmatest: dma0chan4-copy0: summary 5000 tests, 0 failures 199 iops 644 KB/s (0)
dmatest: dma0chan5-copy0: summary 5000 tests, 0 failures 199 iops 645 KB/s (0)
dmatest: dma0chan6-copy0: summary 5000 tests, 0 failures 199 iops 637 KB/s (0)
dmatest: dma0chan24-copy: summary 5000 tests, 0 failures 199 iops 638 KB/s (0)
dmatest: dma0chan16-copy: summary 5000 tests, 0 failures 199 iops 638 KB/s (0)

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:36:38 +05:30
Peter Ujfalusi
e8a5e79c17 dmaengine: omap-dma: Clean up the prep_slave_sg sg list walk code
The for_each_sg() macro's last parameter is inteded to be used as counter.
We can use 'i' instead of 'j' within the loop for indexes.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:36:38 +05:30
Peter Ujfalusi
adf850bcca dmaengine: omap-dma: Correct status reporting for memcpy
During mem copy both src and dst position moves at the same pace. Check the
dst position for progress reporting.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 13:36:38 +05:30
Julia Lawall
2bb129ebb2 dmaengine: ioatdma: constify dca_ops structures
The dca_ops structure is never modified, so declare it as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 09:27:32 +05:30
Dave Jiang
d3cd63f91b dmaengine: IOATDMA: Cleanup pre v3.0 chansts register reads
Remove pre-3.0 channel status reads. 3.0 and later chansts register
is 64bit and can be read 64bit. This was clarified with the hardware
architects and since the driver now only support 3.0+ we don't need the
legacy support

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 09:10:46 +05:30
M'boumba Cedric Madianga
b341b4a13c ARM: configs: Add STM32 DMA support in STM32 defconfig
This patch adds STM32 DMA support in stm32_defconfig file

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:56:11 +05:30
M'boumba Cedric Madianga
d8b468394f dmaengine: Add STM32 DMA driver
This patch adds support for the STM32 DMA controller.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:56:10 +05:30
M'boumba Cedric Madianga
5827a4bae9 dt-bindings: Document the STM32 DMA bindings
This patch adds documentation of device tree bindings for the STM32 dma
controller.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:55:56 +05:30
Robert Jarzmik
d3651b8e5c dmaengine: pxa_dma: declare transfer are reusable
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>
2015-11-16 08:32:16 +05:30
Robert Jarzmik
9eeacd3a2f dmaengine: enable DMA_CTRL_REUSE
In the current state, the capability of transfer reuse can neither be
set by a slave dmaengine driver, nor used by a client driver, because
the capability is not available to dma_get_slave_caps().

Fix this by adding a way to declare the capability.

Fixes: 272420214d ("dmaengine: Add DMA_CTRL_REUSE")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:32:16 +05:30
Robert Jarzmik
13bb26ae88 dmaengine: virt-dma: don't always free descriptor upon completion
This patch attempts to enhance the case of a transfer submitted multiple
times, and where the cost of creating the descriptors chain is not
negligible.

This happens with big video buffers (several megabytes, ie. several
thousands of linked descriptors in one scatter-gather list). In these
cases, a video driver would want to do :
 - tx = dmaengine_prep_slave_sg()
 - dma_engine_submit(tx);
 - dma_async_issue_pending()
 - wait for video completion
 - read video data (or not, skipping a frame is also possible)
 - dma_engine_submit(tx)
   => here, the descriptors chain recalculation will take time
   => the dma coherent allocation over and over might create holes in
      the dma pool, which is counter-productive.
 - dma_async_issue_pending()
 - etc ...

In order to cope with this case, virt-dma is modified to prevent freeing
the descriptors upon completion if DMA_CTRL_REUSE flag is set in the
transfer.

This patch is a respin of the former DMA_CTRL_ACK approach, which was
reverted due to a regression in audio drivers.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:32:16 +05:30
Lars-Peter Clausen
bc0e734516 ALSA: pcm_dmaengine: Properly synchronize DMA on shutdown
Use the new dmaengine_synchronize() function to make sure that all complete
callbacks have finished running before the runtime data, which is accessed
in the completed callback, is freed.

This fixes a long standing use-after-free race condition that has been
observed on some systems.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:28:52 +05:30
Lars-Peter Clausen
860dd64c43 dmaengine: axi_dmac: Add synchronization support
Implement the new device_synchronize() callback to allow proper
synchronization when stopping a channel. Since the driver already makes
sure that no new complete callbacks are scheduled after the
device_terminate_all() callback has been called, all left to do in the
device_synchronize() callback is to wait for all currently running complete
callbacks to finish.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:28:52 +05:30
Lars-Peter Clausen
2ed086296e dmaengine: virt-dma: Add synchronization helper function
Add a synchronize helper function for the virt-dma library. The function
makes sure that any scheduled descriptor complete callbacks have finished
running before the function returns.

This needs to be called by drivers using virt-dma in their
device_synchronize() callback. Depending on the driver additional
operations might be necessary in addition to calling vchan_synchronize() to
ensure proper synchronization.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:28:52 +05:30