6.6-stable review patch. If anyone has any objections, please let me know.
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From: Leo Yan leo.yan@arm.com
[ Upstream commit 40c0cdc9cbbebae9f43bef1cab9ce152318d0cce ]
The atclk is an optional clock for the CoreSight ETMv4, but the driver misses to initialize it.
This change enables atclk in probe of the ETMv4 driver, and dynamically control the clock during suspend and resume.
No need to check the driver data and clock pointer in the runtime suspend and resume, so remove checks. And add error handling in the resume function.
Add a minor fix to the comment format when adding the atclk field.
Fixes: 2e1cdfe184b5 ("coresight-etm4x: Adding CoreSight ETM4x driver") Reviewed-by: Anshuman Khandual anshuman.khandual@arm.com Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Tested-by: James Clark james.clark@linaro.org Signed-off-by: Leo Yan leo.yan@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Link: https://lore.kernel.org/r/20250731-arm_cs_fix_clock_v4-v6-3-1dfe10bb3f6f@arm... Signed-off-by: Sasha Levin sashal@kernel.org --- .../coresight/coresight-etm4x-core.c | 20 ++++++++++++++----- drivers/hwtracing/coresight/coresight-etm4x.h | 4 +++- 2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 625582f7dc34c..e4d8d446ea4d3 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -2118,6 +2118,10 @@ static int etm4_probe(struct device *dev) if (WARN_ON(!drvdata)) return -ENOMEM;
+ drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk"); + if (IS_ERR(drvdata->atclk)) + return PTR_ERR(drvdata->atclk); + if (pm_save_enable == PARAM_PM_SAVE_FIRMWARE) pm_save_enable = coresight_loses_context_with_cpu(dev) ? PARAM_PM_SAVE_SELF_HOSTED : PARAM_PM_SAVE_NEVER; @@ -2369,8 +2373,8 @@ static int etm4_runtime_suspend(struct device *dev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
- if (drvdata->pclk && !IS_ERR(drvdata->pclk)) - clk_disable_unprepare(drvdata->pclk); + clk_disable_unprepare(drvdata->atclk); + clk_disable_unprepare(drvdata->pclk);
return 0; } @@ -2378,11 +2382,17 @@ static int etm4_runtime_suspend(struct device *dev) static int etm4_runtime_resume(struct device *dev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(dev); + int ret; + + ret = clk_prepare_enable(drvdata->pclk); + if (ret) + return ret;
- if (drvdata->pclk && !IS_ERR(drvdata->pclk)) - clk_prepare_enable(drvdata->pclk); + ret = clk_prepare_enable(drvdata->atclk); + if (ret) + clk_disable_unprepare(drvdata->pclk);
- return 0; + return ret; } #endif
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index d72f742b41054..d8b8102d790cc 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -920,7 +920,8 @@ struct etmv4_save_state {
/** * struct etm4_drvdata - specifics associated to an ETM component - * @pclk APB clock if present, otherwise NULL + * @pclk: APB clock if present, otherwise NULL + * @atclk: Optional clock for the core parts of the ETMv4. * @base: Memory mapped base address for this component. * @csdev: Component vitals needed by the framework. * @spinlock: Only one at a time pls. @@ -988,6 +989,7 @@ struct etmv4_save_state { */ struct etmv4_drvdata { struct clk *pclk; + struct clk *atclk; void __iomem *base; struct coresight_device *csdev; spinlock_t spinlock;