Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 9 Dec 2021 11:00:40 +0000 | Subject | Re: [PATCH 2/3] coresight: Fail to open with return stacks if they are unavailable | From | Suzuki K Poulose <> |
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On 08/12/2021 16:09, James Clark wrote: > Maintain consistency with the other options by failing to open when they > aren't supported. For example ETM_OPT_TS, ETM_OPT_CTXTID2 and the newly > added ETM_OPT_BRANCH_BROADCAST all return with -EINVAL if they are > requested but not supported by hardware. > > The consequence of not doing this is that the user may not be > aware that they are not enabling the feature as it is silently disabled. > > Signed-off-by: James Clark <james.clark@arm.com> > --- > drivers/hwtracing/coresight/coresight-etm4x-core.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index d2bafb50c66a..0a9bb943a5e5 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -674,10 +674,15 @@ static int etm4_parse_event_config(struct coresight_device *csdev, > } > > /* return stack - enable if selected and supported */ > - if ((attr->config & BIT(ETM_OPT_RETSTK)) && drvdata->retstack) > - /* bit[12], Return stack enable bit */ > - config->cfg |= BIT(12); > - > + if (attr->config & BIT(ETM_OPT_RETSTK)) { > + if (!drvdata->retstack) { > + ret = -EINVAL; > + goto out; > + } else { > + /* bit[12], Return stack enable bit */ > + config->cfg |= BIT(12); > + }
nit: While at this, please could you change the hard coded value to ETM4_CFG_BIT_RETSTK ?
Otherwise, looks good to me
Suzuki
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