On 13/03/2025 2:40 pm, Leo Yan wrote:
On Tue, Feb 11, 2025 at 10:39:40AM +0000, James Clark wrote:
Add a dev_dbg() message so that external debugger conflicts are more visible. There are multiple reasons for -EBUSY so a message for this particular one could be helpful. Add errors for and enumerate all the other cases that are impossible.
Signed-off-by: James Clark james.clark@linaro.org
drivers/hwtracing/coresight/coresight-core.c | 48 ++++++++++++-------- drivers/hwtracing/coresight/coresight-priv.h | 5 +- 2 files changed, 34 insertions(+), 19 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 7b53165c93af..7fe5d5d432c4 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -133,16 +133,6 @@ static inline u32 coresight_read_claim_tags(struct csdev_access *csa) csdev_access_relaxed_read32(csa, CORESIGHT_CLAIMCLR)); }
-static inline bool coresight_is_claimed_self_hosted(struct csdev_access *csa) -{
return coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED;-}
-static inline bool coresight_is_claimed_any(struct coresight_device *csdev) -{
return coresight_read_claim_tags(&csdev->access) != 0;-}
- static inline void coresight_set_self_claim_tag(struct csdev_access *csa) { csdev_access_relaxed_write32(csa, CORESIGHT_CLAIM_SELF_HOSTED,
@@ -169,18 +159,40 @@ static inline void coresight_clear_self_claim_tag(struct csdev_access *csa) */ int coresight_claim_device_unlocked(struct coresight_device *csdev) {
int tag;struct csdev_access *csa;if (WARN_ON(!csdev)) return -EINVAL;
if (coresight_is_claimed_any(csdev))
csa = &csdev->access;tag = coresight_read_claim_tags(csa);switch (tag) {case CORESIGHT_CLAIM_FREE:coresight_set_self_claim_tag(csa);if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)return 0;It would be a rare case if a failure happens here. Seems to me, it would be valuable to print a log for this edge case.
Otherwise, looks good to me.
Yeah I can add dev_dbg("Busy: Couldn't set self claim tag"). Just to distinguish this race case from the other busy case.