| Message ID | 1473416289-30882-1-git-send-email-zhang.chunyan@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 9 September 2016 at 04:18, Chunyan Zhang <zhang.chunyan@linaro.org> wrote: > 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> > --- > drivers/hwtracing/coresight/coresight-stm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c > index 73be58a..6291ce1 100644 > --- a/drivers/hwtracing/coresight/coresight-stm.c > +++ b/drivers/hwtracing/coresight/coresight-stm.c > @@ -399,10 +399,10 @@ 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); > > -- > 2.7.4 > Applied, but I had to change the title to "coresight: stm: return error code instead of zero in .packet()" as the previous one exceeded 80 characters. Thanks, Mathieu
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c index 73be58a..6291ce1 100644 --- a/drivers/hwtracing/coresight/coresight-stm.c +++ b/drivers/hwtracing/coresight/coresight-stm.c @@ -399,10 +399,10 @@ 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);
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> --- drivers/hwtracing/coresight/coresight-stm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)