From: Andy Shevchenko andriy.shevchenko@linux.intel.com
[ Upstream commit aa72f1d20ee973d68f26d46fce5e1cf6f9b7e1ca ]
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 seraj.alijan@sondrel.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20200428113518.70620-1-andriy.shevchenko@linux.int... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/dmatest.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index 4993e3e5c5b01..364dd34799d45 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -240,7 +240,7 @@ static bool is_threaded_test_run(struct dmatest_info *info) struct dmatest_thread *thread;
list_for_each_entry(thread, &dtc->threads, node) { - if (!thread->done) + if (!thread->done && !thread->pending) return true; } }