| Message ID | 20230106152331.1374973-2-james.clark@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: cti: Add PM runtime call in enable_store | expand |
Hi James, Thanks for fixing this. On 06/01/2023 15:23, James Clark wrote: > Writing 0 to the enable control repeatedly results in a negative value > for enable_req_count. After this, writing 1 to the enable control > appears to not work until the count returns to positive. > > Change it so that it's impossible for enable_req_count to be < 0. I prefer rephrasing the following : > Returning an error will also allow us to decide whether to call > runtime_pm_put() or not in the following commit. "Return an error to indicate the disable request was invalid" and don't mention the forward dependency. > May be also add ? Fixes: 835d722ba10a ("coresight: cti: Initial CoreSight CTI Driver") > Signed-off-by: James Clark <james.clark@arm.com> Rest looks fine to me. Suzuki > --- > drivers/hwtracing/coresight/coresight-cti-core.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c > index d2cf4f4848e1..838872f2484d 100644 > --- a/drivers/hwtracing/coresight/coresight-cti-core.c > +++ b/drivers/hwtracing/coresight/coresight-cti-core.c > @@ -151,9 +151,16 @@ static int cti_disable_hw(struct cti_drvdata *drvdata) > { > struct cti_config *config = &drvdata->config; > struct coresight_device *csdev = drvdata->csdev; > + int ret = 0; > > spin_lock(&drvdata->spinlock); > > + /* don't allow negative refcounts, return an error */ > + if (!atomic_read(&drvdata->config.enable_req_count)) { > + ret = -EINVAL; > + goto cti_not_disabled; > + } > + > /* check refcount - disable on 0 */ > if (atomic_dec_return(&drvdata->config.enable_req_count) > 0) > goto cti_not_disabled; > @@ -171,12 +178,12 @@ static int cti_disable_hw(struct cti_drvdata *drvdata) > coresight_disclaim_device_unlocked(csdev); > CS_LOCK(drvdata->base); > spin_unlock(&drvdata->spinlock); > - return 0; > + return ret; > > /* not disabled this call */ > cti_not_disabled: > spin_unlock(&drvdata->spinlock); > - return 0; > + return ret; > } > > void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value)
diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c index d2cf4f4848e1..838872f2484d 100644 --- a/drivers/hwtracing/coresight/coresight-cti-core.c +++ b/drivers/hwtracing/coresight/coresight-cti-core.c @@ -151,9 +151,16 @@ static int cti_disable_hw(struct cti_drvdata *drvdata) { struct cti_config *config = &drvdata->config; struct coresight_device *csdev = drvdata->csdev; + int ret = 0; spin_lock(&drvdata->spinlock); + /* don't allow negative refcounts, return an error */ + if (!atomic_read(&drvdata->config.enable_req_count)) { + ret = -EINVAL; + goto cti_not_disabled; + } + /* check refcount - disable on 0 */ if (atomic_dec_return(&drvdata->config.enable_req_count) > 0) goto cti_not_disabled; @@ -171,12 +178,12 @@ static int cti_disable_hw(struct cti_drvdata *drvdata) coresight_disclaim_device_unlocked(csdev); CS_LOCK(drvdata->base); spin_unlock(&drvdata->spinlock); - return 0; + return ret; /* not disabled this call */ cti_not_disabled: spin_unlock(&drvdata->spinlock); - return 0; + return ret; } void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value)
Writing 0 to the enable control repeatedly results in a negative value for enable_req_count. After this, writing 1 to the enable control appears to not work until the count returns to positive. Change it so that it's impossible for enable_req_count to be < 0. Returning an error will also allow us to decide whether to call runtime_pm_put() or not in the following commit. Signed-off-by: James Clark <james.clark@arm.com> --- drivers/hwtracing/coresight/coresight-cti-core.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)