From: Vladimir Murzin vladimir.murzin@arm.com
[ Upstream commit ce65d55f92a67e247f4d799e581cf9fed677871c ]
Andy reported that commit 6b41030fdc79 ("dmaengine: dmatest: Restore default for channel") broke his scripts for the case where "busy" channel is used for configuration with expectation that run command would do nothing. Instead, behavior was (unintentionally) changed to treat such case as under-configuration and progress with defaults, i.e. run command would start a test with default setting for channel (which would use all channels).
Restore original behavior with tracking status of channel setter so we can distinguish between misconfigured and under-configured cases in run command and act accordingly.
Fixes: 6b41030fdc79 ("dmaengine: dmatest: Restore default for channel") Reported-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Tested-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com Tested-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20200922115847.30100-1-andriy.shevchenko@linux.int... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/dmatest.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index 604f803579312..323822372b4ce 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -129,6 +129,7 @@ struct dmatest_params { * @nr_channels: number of channels under test * @lock: access protection to the fields of this structure * @did_init: module has been initialized completely + * @last_error: test has faced configuration issues */ static struct dmatest_info { /* Test parameters */ @@ -137,6 +138,7 @@ static struct dmatest_info { /* Internal state */ struct list_head channels; unsigned int nr_channels; + int last_error; struct mutex lock; bool did_init; } test_info = { @@ -1175,10 +1177,22 @@ static int dmatest_run_set(const char *val, const struct kernel_param *kp) return ret; } else if (dmatest_run) { if (!is_threaded_test_pending(info)) { - pr_info("No channels configured, continue with any\n"); - if (!is_threaded_test_run(info)) - stop_threaded_test(info); - add_threaded_test(info); + /* + * We have nothing to run. This can be due to: + */ + ret = info->last_error; + if (ret) { + /* 1) Misconfiguration */ + pr_err("Channel misconfigured, can't continue\n"); + mutex_unlock(&info->lock); + return ret; + } else { + /* 2) We rely on defaults */ + pr_info("No channels configured, continue with any\n"); + if (!is_threaded_test_run(info)) + stop_threaded_test(info); + add_threaded_test(info); + } } start_threaded_tests(info); } else { @@ -1195,7 +1209,7 @@ static int dmatest_chan_set(const char *val, const struct kernel_param *kp) struct dmatest_info *info = &test_info; struct dmatest_chan *dtc; char chan_reset_val[20]; - int ret = 0; + int ret;
mutex_lock(&info->lock); ret = param_set_copystring(val, kp); @@ -1250,12 +1264,14 @@ static int dmatest_chan_set(const char *val, const struct kernel_param *kp) goto add_chan_err; }
+ info->last_error = ret; mutex_unlock(&info->lock);
return ret;
add_chan_err: param_set_copystring(chan_reset_val, kp); + info->last_error = ret; mutex_unlock(&info->lock);
return ret;