From: Mao Jinlong quic_jinlmao@quicinc.com
[ Upstream commit eff674a9b86a6ffdd10c3af3863545acf7f1ce4f ]
In commit 6746eae4bbad ("coresight: cti: Fix hang in cti_disable_hw()") PM runtime calls are removed from cti_enable_hw/cti_disable_hw. When enabling CTI by writing enable sysfs node, clock for accessing CTI register won't be enabled. Device will crash due to register access issue. Add PM runtime call in enable_store to fix this issue.
Fixes: 6746eae4bbad ("coresight: cti: Fix hang in cti_disable_hw()") Signed-off-by: Mao Jinlong quic_jinlmao@quicinc.com [Change to only call pm_runtime_put if a disable happened] Tested-by: Jinlong Mao quic_jinlmao@quicinc.com Signed-off-by: James Clark james.clark@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Link: https://lore.kernel.org/r/20230110110736.2709917-3-james.clark@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwtracing/coresight/coresight-cti-sysfs.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c index 6d59c815ecf5e..71e7a8266bb32 100644 --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c @@ -108,10 +108,19 @@ static ssize_t enable_store(struct device *dev, if (ret) return ret;
- if (val) + if (val) { + ret = pm_runtime_resume_and_get(dev->parent); + if (ret) + return ret; ret = cti_enable(drvdata->csdev); - else + if (ret) + pm_runtime_put(dev->parent); + } else { ret = cti_disable(drvdata->csdev); + if (!ret) + pm_runtime_put(dev->parent); + } + if (ret) return ret; return size;