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authorChunyan Zhang <zhang.chunyan@linaro.org>2016-11-29 17:47:11 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-29 20:05:32 +0100
commit9870ef5c584e2ec7a5e9614e6b29fcc06d8bc139 (patch)
tree01da2ab4820e849ba64cba8ec7ec04d8797d93aa /drivers/hwtracing
parentMerge tag 'stm-for-greg-20161118' of git://git.kernel.org/pub/scm/linux/kerne... (diff)
downloadlinux-9870ef5c584e2ec7a5e9614e6b29fcc06d8bc139.tar.xz
linux-9870ef5c584e2ec7a5e9614e6b29fcc06d8bc139.zip
coresight: stm: return error code instead of zero in .packet()
In STM framework driver, the trace data writing loop would keep running until it received a negative return value or the whole trace packet has been written to STM device. So if the .packet() of STM device always returns zero since the device is not enabled or the parameter isn't supported, STM framework driver will stall into a dead loop. Returning -EACCES (Permission denied) in .packet() if the device is disabled makes more sense, and this is the same for returning -EINVAL if the channel passed into is not supported. Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight-stm.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index 49e0f1b925a5..d397849c2c6a 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -419,10 +419,10 @@ static ssize_t stm_generic_packet(struct stm_data *stm_data,
struct stm_drvdata, stm);
if (!(drvdata && local_read(&drvdata->mode)))
- return 0;
+ return -EACCES;
if (channel >= drvdata->numsp)
- return 0;
+ return -EINVAL;
ch_addr = (unsigned long)stm_channel_addr(drvdata, channel);