Messages in this thread | | | Subject | Re: [PATCH 2/3] coresight: Fail to open with return stacks if they are unavailable | From | James Clark <> | Date | Thu, 9 Dec 2021 11:13:55 +0000 |
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On 09/12/2021 11:00, Suzuki K Poulose wrote: > 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 ? > I started changing them all because I had trouble searching for bits by name but then I thought it would snowball into a bigger change so I undid it.
I think I'll just go and do it now if it's an issue here.
> Otherwise, looks good to me > > Suzuki
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