linux-toradex.git/drivers/dma/fsldma.h, branch v3.14.50 Linux kernel for Apalis and Colibri modules DMA: Freescale: change BWC from 256 bytes to 1024 bytes 2014-01-20T07:43:22+00:00 Hongbo Zhang hongbo.zhang@freescale.com 2014-01-16T06:10:53+00:00 0ca583a239a854fd403bf8b659cdff8c603372c9 Freescale DMA has a feature of BandWidth Control (ab. BWC), which is currently 256 bytes and should be changed to 1024 bytes for best DMA throughput. Changing BWC from 256 to 1024 will improve DMA performance much, in cases whatever one channel is running or multi channels are running simultanously, large or small buffers are copied. And this change doesn't impact memory access performance remarkably, lmbench tests show that for some cases the memory performance are decreased very slightly, while the others are even better. Tested on T4240. Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
Freescale DMA has a feature of BandWidth Control (ab. BWC), which is currently
256 bytes and should be changed to 1024 bytes for best DMA throughput.
Changing BWC from 256 to 1024 will improve DMA performance much, in cases
whatever one channel is running or multi channels are running simultanously,
large or small buffers are copied.  And this change doesn't impact memory
access performance remarkably, lmbench tests show that for some cases the
memory performance are decreased very slightly, while the others are even
better.
Tested on T4240.

Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
DMA: Freescale: update driver to support 8-channel DMA engine 2013-11-13T08:56:27+00:00 Hongbo Zhang hongbo.zhang@freescale.com 2013-09-26T09:33:43+00:00 8de7a7d95049bdbe454ade7add08d893efe5a456 This patch adds support to 8-channel DMA engine, thus the driver works for both the new 8-channel and the legacy 4-channel DMA engines. Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
This patch adds support to 8-channel DMA engine, thus the driver works for both
the new 8-channel and the legacy 4-channel DMA engines.

Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: move last completed cookie into generic dma_chan structure 2012-03-13T06:06:06+00:00 Russell King - ARM Linux linux@arm.linux.org.uk 2012-03-06T22:34:06+00:00 4d4e58de32a192fea65ab84509d17d199bd291c8 Every DMA engine implementation declares a last completed dma cookie in their private dma channel structures. This is pointless, and forces driver specific code. Move this out into the common dma_chan structure. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Tested-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Jassi Brar <jassisinghbrar@gmail.com> [imx-sdma.c & mxs-dma.c] Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com> 
Every DMA engine implementation declares a last completed dma cookie
in their private dma channel structures.  This is pointless, and
forces driver specific code.  Move this out into the common dma_chan
structure.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
fsldma: fix controller lockups 2011-03-12T01:52:36+00:00 Ira Snyder iws@ovro.caltech.edu 2011-03-03T07:54:58+00:00 f04cd40701deace2efb9edd7120e59366bda2118 Enabling poisoning in the dmapool API quickly showed that the DMA controller was fetching descriptors that should not have been in use. This has caused intermittent controller lockups during testing. I have been unable to figure out the exact set of conditions which cause this to happen. However, I believe it is related to the driver using the hardware registers to track whether the controller is busy or not. The code can incorrectly decide that the hardware is idle due to lag between register writes and the hardware actually becoming busy. To fix this, the driver has been reworked to explicitly track the state of the hardware, rather than try to guess what it is doing based on the register values. This has passed dmatest with 10 threads per channel, 100000 iterations per thread several times without error. Previously, this would fail within a few seconds. Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Enabling poisoning in the dmapool API quickly showed that the DMA
controller was fetching descriptors that should not have been in use.
This has caused intermittent controller lockups during testing.

I have been unable to figure out the exact set of conditions which cause
this to happen. However, I believe it is related to the driver using the
hardware registers to track whether the controller is busy or not. The
code can incorrectly decide that the hardware is idle due to lag between
register writes and the hardware actually becoming busy.

To fix this, the driver has been reworked to explicitly track the state
of the hardware, rather than try to guess what it is doing based on the
register values.

This has passed dmatest with 10 threads per channel, 100000 iterations
per thread several times without error. Previously, this would fail
within a few seconds.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
fsldma: minor codingstyle and consistency fixes 2011-03-12T01:52:36+00:00 Ira Snyder iws@ovro.caltech.edu 2011-03-03T07:54:57+00:00 31f4306c83a2daa3e348056b720de511bffe5a9b This fixes some minor violations of the coding style. It also changes the style of the device_prep_dma_*() function definitions so they are identical. Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
This fixes some minor violations of the coding style. It also changes
the style of the device_prep_dma_*() function definitions so they are
identical.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
fsldma: use channel name in printk output 2011-03-12T01:52:36+00:00 Ira Snyder iws@ovro.caltech.edu 2011-03-03T07:54:55+00:00 b158471ef63bf399165db96e945a828096502d9d This makes debugging the driver much easier when multiple channels are running concurrently. In addition, you can see how much descriptor memory each channel has allocated via the dmapool API in sysfs. Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
This makes debugging the driver much easier when multiple channels are
running concurrently. In addition, you can see how much descriptor
memory each channel has allocated via the dmapool API in sysfs.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
fsldma: fix issue of slow dma 2010-12-13T22:05:27+00:00 Forrest Shi b29237@freescale.com 2010-12-09T08:14:04+00:00 f3c677b997757326e1f29d33060719a6a5091950 Fixed fsl dma slow issue by initializing dma mode register with bandwidth control. It boosts dma performance and should works with 85xx board. Signed-off-by: Forrest Shi <b29237@freescale.com> Signed-off-by: Li Yang <leoli@freescale.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Fixed fsl dma slow issue by initializing dma mode register with
bandwidth control. It boosts dma performance and should works
with 85xx board.

Signed-off-by: Forrest Shi <b29237@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
fsldma: major cleanups and fixes 2010-02-02T21:51:42+00:00 Ira Snyder iws@ovro.caltech.edu 2010-01-06T13:34:06+00:00 9c3a50b7d7ec45da34e73cac66cde12dd6092dd8 Fix locking. Use two queues in the driver, one for pending transacions, and one for transactions which are actually running on the hardware. Call dma_run_dependencies() on descriptor cleanup so that the async_tx API works correctly. There are a number of places throughout the code where lists of descriptors are freed in a loop. Create functions to handle this, and use them instead of open-coding the loop each time. Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Fix locking. Use two queues in the driver, one for pending transacions, and
one for transactions which are actually running on the hardware. Call
dma_run_dependencies() on descriptor cleanup so that the async_tx API works
correctly.

There are a number of places throughout the code where lists of descriptors
are freed in a loop. Create functions to handle this, and use them instead
of open-coding the loop each time.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
fsldma: clean up the OF subsystem routines 2010-02-02T21:51:41+00:00 Ira Snyder iws@ovro.caltech.edu 2010-01-06T13:34:03+00:00 e7a29151de1bd52081f27f149b68074fac0323be This fixes some errors in the cleanup paths of the OF subsystem, including missing checks for ioremap failing. Also, some variables were renamed for brevity. Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
This fixes some errors in the cleanup paths of the OF subsystem, including
missing checks for ioremap failing. Also, some variables were renamed for
brevity.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
fsldma: rename dest to dst for uniformity 2010-02-02T21:51:41+00:00 Ira Snyder iws@ovro.caltech.edu 2010-01-06T13:34:02+00:00 738f5f7e1ae876448cb7d9c82bea258b69386647 Most functions in the standard library use "dst" as a parameter, rather than "dest". This renames all use of "dest" to "dst" to match the usual convention. Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Most functions in the standard library use "dst" as a parameter, rather
than "dest". This renames all use of "dest" to "dst" to match the usual
convention.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>