linux.git/drivers/dma/dmatest.c, branch v5.8

dmaengine: dmatest: stop completed threads when running without set channel

2020-07-06T05:12:17+00:00

The completed threads were not cleared and consequent run would result
threads accumulating:

echo 800000 > /sys/module/dmatest/parameters/test_buf_size
echo 2000 > /sys/module/dmatest/parameters/timeout
echo 50 > /sys/module/dmatest/parameters/iterations
echo 1 > /sys/module/dmatest/parameters/max_channels
echo "" > /sys/module/dmatest/parameters/channel
[  237.507265] dmatest: Added 1 threads using dma1chan2
echo 1 > /sys/module/dmatest/parameters/run
[  244.713360] dmatest: Started 1 threads using dma1chan2
[  246.117680] dmatest: dma1chan2-copy0: summary 50 tests, 0 failures 2437.47 iops 977623 KB/s (0)

echo 1 > /sys/module/dmatest/parameters/run
[  292.381471] dmatest: No channels configured, continue with any
[  292.389307] dmatest: Added 1 threads using dma1chan3
[  292.394302] dmatest: Started 1 threads using dma1chan2
[  292.399454] dmatest: Started 1 threads using dma1chan3
[  293.800835] dmatest: dma1chan3-copy0: summary 50 tests, 0 failures 2624.53 iops 975014 KB/s (0)

echo 1 > /sys/module/dmatest/parameters/run
[  307.301429] dmatest: No channels configured, continue with any
[  307.309212] dmatest: Added 1 threads using dma1chan4
[  307.314197] dmatest: Started 1 threads using dma1chan2
[  307.319343] dmatest: Started 1 threads using dma1chan3
[  307.324492] dmatest: Started 1 threads using dma1chan4
[  308.730773] dmatest: dma1chan4-copy0: summary 50 tests, 0 failures 2390.28 iops 965436 KB/s (0)

Fixes: 6b41030fdc79 ("dmaengine: dmatest: Restore default for channel")
Reported-by: Grygorii Strashko 
Signed-off-by: Peter Ujfalusi 
Link: https://lore.kernel.org/r/20200701101225.8607-1-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul

Merge tag 'dmaengine-5.8-rc1' of git://git.infradead.org/users/vkoul/slave-dma

2020-06-10T18:03:04+00:00

Pull dmaengine updates from Vinod Koul:
 "A fairly small dmaengine update which includes mostly driver updates
  (dmatest, dw-edma, ioat, mmp-tdma and k3-udma) along with Renesas
  binding update to json-schema"

* tag 'dmaengine-5.8-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (39 commits)
  dmaengine: imx-sdma: initialize all script addresses
  dmaengine: ti: k3-udma: Use proper return code in alloc_chan_resources
  dmaengine: ti: k3-udma: Remove udma_chan.in_ring_cnt
  dmaengine: ti: k3-udma: Add missing dma_sync call for rx flush descriptor
  dmaengine: at_xdmac: Replace zero-length array with flexible-array
  dmaengine: at_hdmac: Replace zero-length array with flexible-array
  dmaengine: qcom: bam_dma: Replace zero-length array with flexible-array
  dmaengine: ti: k3-udma: Use PTR_ERR_OR_ZERO() to simplify code
  dmaengine: moxart-dma: Drop pointless static qualifier in moxart_probe()
  dmaengine: sf-pdma: Simplify the error handling path in 'sf_pdma_probe()'
  dmaengine: qcom_hidma: use true,false for bool variable
  dmaengine: dw-edma: support local dma device transfer semantics
  dmaengine: Fix doc strings to satisfy validation script
  dmaengine: Include dmaengine.h into dmaengine.c
  dmaengine: dmatest: Describe members of struct dmatest_info
  dmaengine: dmatest: Describe members of struct dmatest_params
  dmaengine: dmatest: Allow negative timeout value to specify infinite wait
  Revert "dmaengine: dmatest: timeout value of -1 should specify infinite wait"
  dmaengine: stm32-dma: direct mode support through device tree
  dt-bindings: dma: add direct mode support through device tree in stm32-dma
  ...

dmaengine: dmatest: Restore default for channel

2020-05-13T11:27:25+00:00

In case of dmatest is built-in and no channel was configured test
doesn't run with:

dmatest: Could not start test, no channels configured

Even though description to "channel" parameter claims that default is
any.

Add default channel back as it used to be rather than reject test with
no channel configuration.

Fixes: d53513d5dc285d9a95a534fc41c5c08af6b60eac ("dmaengine: dmatest: Add support for multi channel testing)
Reported-by: Dijil Mohan 
Signed-off-by: Vladimir Murzin 
Link: https://lore.kernel.org/r/20200429071522.58148-1-vladimir.murzin@arm.com
Signed-off-by: Vinod Koul

dmaengine: dmatest: Fix process hang when reading 'wait' parameter

2020-04-28T16:16:35+00:00

If we do

  % echo 1 > /sys/module/dmatest/parameters/run
  [  115.851124] dmatest: Could not start test, no channels configured

  % echo dma8chan7 > /sys/module/dmatest/parameters/channel
  [  127.563872] dmatest: Added 1 threads using dma8chan7

  % cat /sys/module/dmatest/parameters/wait
  ... !!! HANG !!! ...

The culprit is the commit 6138f967bccc

  ("dmaengine: dmatest: Use fixed point div to calculate iops")

which makes threads not to run, but pending and being kicked off by writing
to the 'run' node. However, it forgot to consider 'wait' routine to avoid
above mentioned case.

In order to fix this, check for really running threads, i.e. with pending
and done flags unset.

It's pity the culprit commit hadn't updated documentation and tested all
possible scenarios.

Fixes: 6138f967bccc ("dmaengine: dmatest: Use fixed point div to calculate iops")
Cc: Seraj Alijan 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20200428113518.70620-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul

dmaengine: dmatest: Describe members of struct dmatest_info

2020-04-27T16:17:52+00:00

Kernel documentation validator complains that not all members of
struct dmatest_info are being described. Describe them all.

Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20200424161147.16895-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul

dmaengine: dmatest: Describe members of struct dmatest_params

2020-04-27T16:17:52+00:00

Kernel documentation validator complains that not all members of
struct dmatest_params are being described. Describe them all.

Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20200424161147.16895-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul

dmaengine: dmatest: Allow negative timeout value to specify infinite wait

2020-04-27T16:17:52+00:00

The dmatest module parameter 'timeout' is documented as accepting a -1 to mean
"infinite timeout". However, an infinite timeout is not advised, nor possible
since the module parameter is an unsigned int, which won't accept a negative
value. Change the parameter type to be signed integer.

Cc: Gary Hook 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20200424161147.16895-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul

Revert "dmaengine: dmatest: timeout value of -1 should specify infinite wait"

2020-04-27T16:17:52+00:00

This reverts commit ed04b7c57c3383ed4573f1d1d1dbdc1108ba0bed.

While it gives a good description what happens, the approach seems too
confusing. Let's fix it in the following patch.

Cc: Gary Hook 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20200424161147.16895-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul

dmaengine: dmatest: Fix iteration non-stop logic

2020-04-27T16:15:35+00:00

Under some circumstances, i.e. when test is still running and about to
time out and user runs, for example,

	grep -H . /sys/module/dmatest/parameters/*

the iterations parameter is not respected and test is going on and on until
user gives

	echo 0 > /sys/module/dmatest/parameters/run

This is not what expected.

The history of this bug is interesting. I though that the commit
  2d88ce76eb98 ("dmatest: add a 'wait' parameter")
is a culprit, but looking closer to the code I think it simple revealed the
broken logic from the day one, i.e. in the commit
  0a2ff57d6fba ("dmaengine: dmatest: add a maximum number of test iterations")
which adds iterations parameter.

So, to the point, the conditional of checking the thread to be stopped being
first part of conjunction logic prevents to check iterations. Thus, we have to
always check both conditions to be able to stop after given iterations.

Since it wasn't visible before second commit appeared, I add a respective
Fixes tag.

Fixes: 2d88ce76eb98 ("dmatest: add a 'wait' parameter")
Cc: Dan Williams 
Cc: Nicolas Ferre 
Signed-off-by: Andy Shevchenko 
Acked-by: Nicolas Ferre 
Link: https://lore.kernel.org/r/20200424161147.16895-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul

dmaengine: dmatest: Add support for completion polling

2019-09-04T04:44:22+00:00

With the polled parameter the DMA drivers can be tested if they can work
correctly when no completion is requested (no DMA_PREP_INTERRUPT and no
callback is provided).

If polled mode is selected then use dma_sync_wait() to execute the test
iteration instead of relying on the completion callback.

Signed-off-by: Peter Ujfalusi 
Link: https://lore.kernel.org/r/20190731071438.24075-1-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul