From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Leo Yan <leo.yan@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Mike Leach <mike.leach@linaro.org>,
James Clark <james.clark@linaro.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 9/9] coresight: Refactor runtime PM
Date: Tue, 10 Jun 2025 15:37:16 +0530 [thread overview]
Message-ID: <dbf2f5b8-49cc-4b66-b32b-a8e149029419@arm.com> (raw)
In-Reply-To: <20250609-arm_cs_fix_clock_v3_public-v3-9-423b3f1f241d@arm.com>
On 09/06/25 9:30 PM, Leo Yan wrote:
> The validation for driver data pointers and clock pointers are redundant
> in the runtime PM callbacks. After a driver's probing, its driver data
> and clocks have been initialized successfully, this ensures it is safe
> to access driver data and clocks in the runtime PM callbacks. A corner
> case is a clock pointer is NULL, in this case, the clock core layer can
> handle it properly. So remove these redundant checking.
>
> In runtime resume, respect values returned from clock function and add
> error handling.
Makes sense.
>
> Signed-off-by: Leo Yan <leo.yan@arm.com>
This looks like a good clean up and streamlining.
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> drivers/hwtracing/coresight/coresight-cpu-debug.c | 8 +++-----
> drivers/hwtracing/coresight/coresight-ctcu-core.c | 8 ++------
> drivers/hwtracing/coresight/coresight-etb10.c | 8 ++------
> drivers/hwtracing/coresight/coresight-etm3x-core.c | 8 ++------
> drivers/hwtracing/coresight/coresight-funnel.c | 21 +++++++++++----------
> drivers/hwtracing/coresight/coresight-replicator.c | 20 +++++++++++---------
> drivers/hwtracing/coresight/coresight-stm.c | 20 +++++++++++---------
> drivers/hwtracing/coresight/coresight-tpiu.c | 20 +++++++++++---------
> 8 files changed, 53 insertions(+), 60 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c
> index 3edfb5d3d02056afcaab4da575d1101c68aeac80..5f21366406aae03edef9e4fb737e19941afb9ac2 100644
> --- a/drivers/hwtracing/coresight/coresight-cpu-debug.c
> +++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c
> @@ -731,8 +731,8 @@ static int debug_runtime_suspend(struct device *dev)
> {
> struct debug_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_disable_unprepare(drvdata->pclk);
> + clk_disable_unprepare(drvdata->pclk);
> +
> return 0;
> }
>
> @@ -740,9 +740,7 @@ static int debug_runtime_resume(struct device *dev)
> {
> struct debug_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_prepare_enable(drvdata->pclk);
> - return 0;
> + return clk_prepare_enable(drvdata->pclk);
> }
> #endif
>
> diff --git a/drivers/hwtracing/coresight/coresight-ctcu-core.c b/drivers/hwtracing/coresight/coresight-ctcu-core.c
> index 75b5114ef652e4a47c53fbd2b7811c1bab575645..c586495e9a088a63cec481a82fd9f4ec7c645160 100644
> --- a/drivers/hwtracing/coresight/coresight-ctcu-core.c
> +++ b/drivers/hwtracing/coresight/coresight-ctcu-core.c
> @@ -278,8 +278,7 @@ static int ctcu_runtime_suspend(struct device *dev)
> {
> struct ctcu_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->apb_clk))
> - clk_disable_unprepare(drvdata->apb_clk);
> + clk_disable_unprepare(drvdata->apb_clk);
>
> return 0;
> }
> @@ -288,10 +287,7 @@ static int ctcu_runtime_resume(struct device *dev)
> {
> struct ctcu_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->apb_clk))
> - clk_prepare_enable(drvdata->apb_clk);
> -
> - return 0;
> + return clk_prepare_enable(drvdata->apb_clk);
> }
> #endif
>
> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
> index 8e81b41eb22264f17606050fa8da277aae05c5cc..35db1b6093d154d67dc567df42f838e2ba3d1d58 100644
> --- a/drivers/hwtracing/coresight/coresight-etb10.c
> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
> @@ -809,8 +809,7 @@ static int etb_runtime_suspend(struct device *dev)
> {
> struct etb_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->atclk);
>
> return 0;
> }
> @@ -819,10 +818,7 @@ static int etb_runtime_resume(struct device *dev)
> {
> struct etb_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_prepare_enable(drvdata->atclk);
> -
> - return 0;
> + return clk_prepare_enable(drvdata->atclk);
> }
> #endif
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> index baba2245b1dfb31f4bf19080e20c33df3a5b854f..45630a1cd32fbd05ec8b2a6979f0174cacce365e 100644
> --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> @@ -925,8 +925,7 @@ static int etm_runtime_suspend(struct device *dev)
> {
> struct etm_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->atclk);
>
> return 0;
> }
> @@ -935,10 +934,7 @@ static int etm_runtime_resume(struct device *dev)
> {
> struct etm_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_prepare_enable(drvdata->atclk);
> -
> - return 0;
> + return clk_prepare_enable(drvdata->atclk);
> }
> #endif
>
> diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
> index 9dcfc5ce8845d9e01bb956dddab0d64de51ec397..3b248e54471a38f501777fe162fea850d1c851b3 100644
> --- a/drivers/hwtracing/coresight/coresight-funnel.c
> +++ b/drivers/hwtracing/coresight/coresight-funnel.c
> @@ -284,11 +284,8 @@ static int funnel_runtime_suspend(struct device *dev)
> {
> struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_disable_unprepare(drvdata->atclk);
> -
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_disable_unprepare(drvdata->pclk);
> + clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->pclk);
>
> return 0;
> }
> @@ -296,13 +293,17 @@ static int funnel_runtime_suspend(struct device *dev)
> static int funnel_runtime_resume(struct device *dev)
> {
> struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = clk_prepare_enable(drvdata->pclk);
> + if (ret)
> + return ret;
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_prepare_enable(drvdata->pclk);
> + ret = clk_prepare_enable(drvdata->atclk);
> + if (ret)
> + clk_disable_unprepare(drvdata->pclk);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_prepare_enable(drvdata->atclk);
> - return 0;
> + return ret;
> }
> #endif
>
> diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
> index e53095603b0c0419bc96a66b23d15bb54e75e634..e6472658235dc479cec91ac18f3737f76f8c74f0 100644
> --- a/drivers/hwtracing/coresight/coresight-replicator.c
> +++ b/drivers/hwtracing/coresight/coresight-replicator.c
> @@ -323,24 +323,26 @@ static int replicator_runtime_suspend(struct device *dev)
> {
> struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->pclk);
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_disable_unprepare(drvdata->pclk);
> return 0;
> }
>
> static int replicator_runtime_resume(struct device *dev)
> {
> struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
> + int ret;
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_prepare_enable(drvdata->pclk);
> + ret = clk_prepare_enable(drvdata->pclk);
> + if (ret)
> + return ret;
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_prepare_enable(drvdata->atclk);
> - return 0;
> + ret = clk_prepare_enable(drvdata->atclk);
> + if (ret)
> + clk_disable_unprepare(drvdata->pclk);
> +
> + return ret;
> }
> #endif
>
> diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
> index ed68d8280b1945f38d1294a5b5f557a614c90c94..28230bbc9df2afec7b426e2fd4d4e4066f51e143 100644
> --- a/drivers/hwtracing/coresight/coresight-stm.c
> +++ b/drivers/hwtracing/coresight/coresight-stm.c
> @@ -957,24 +957,26 @@ static int stm_runtime_suspend(struct device *dev)
> {
> struct stm_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->pclk);
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_disable_unprepare(drvdata->pclk);
> return 0;
> }
>
> static int stm_runtime_resume(struct device *dev)
> {
> struct stm_drvdata *drvdata = dev_get_drvdata(dev);
> + int ret;
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_prepare_enable(drvdata->pclk);
> + ret = clk_prepare_enable(drvdata->pclk);
> + if (ret)
> + return ret;
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_prepare_enable(drvdata->atclk);
> - return 0;
> + ret = clk_prepare_enable(drvdata->atclk);
> + if (ret)
> + clk_disable_unprepare(drvdata->pclk);
> +
> + return ret;
> }
> #endif
>
> diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
> index 1c5c2a82971490888c45508c68b516ab7dbf3eeb..9463afdbda8ad74eee78c72185fe7603f81b7888 100644
> --- a/drivers/hwtracing/coresight/coresight-tpiu.c
> +++ b/drivers/hwtracing/coresight/coresight-tpiu.c
> @@ -206,24 +206,26 @@ static int tpiu_runtime_suspend(struct device *dev)
> {
> struct tpiu_drvdata *drvdata = dev_get_drvdata(dev);
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->atclk);
> + clk_disable_unprepare(drvdata->pclk);
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_disable_unprepare(drvdata->pclk);
> return 0;
> }
>
> static int tpiu_runtime_resume(struct device *dev)
> {
> struct tpiu_drvdata *drvdata = dev_get_drvdata(dev);
> + int ret;
>
> - if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
> - clk_prepare_enable(drvdata->pclk);
> + ret = clk_prepare_enable(drvdata->pclk);
> + if (ret)
> + return ret;
>
> - if (drvdata && !IS_ERR(drvdata->atclk))
> - clk_prepare_enable(drvdata->atclk);
> - return 0;
> + ret = clk_prepare_enable(drvdata->atclk);
> + if (ret)
> + clk_disable_unprepare(drvdata->pclk);
> +
> + return ret;
> }
> #endif
>
>
prev parent reply other threads:[~2025-06-10 10:07 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-09 16:00 [PATCH v3 0/9] coresight: Fix and improve clock usage Leo Yan
2025-06-09 16:00 ` [PATCH v3 1/9] coresight: tmc: Support atclk Leo Yan
2025-06-09 16:00 ` [PATCH v3 2/9] coresight: catu: " Leo Yan
2025-06-09 16:00 ` [PATCH v3 3/9] coresight: etm4x: " Leo Yan
2025-06-09 16:00 ` [PATCH v3 4/9] coresight: Appropriately disable programming clocks Leo Yan
2025-06-09 16:11 ` Suzuki K Poulose
2025-06-09 16:38 ` Leo Yan
2025-06-24 4:23 ` Anshuman Khandual
2025-06-24 4:37 ` Anshuman Khandual
2025-06-09 16:00 ` [PATCH v3 5/9] coresight: Appropriately disable trace bus clocks Leo Yan
2025-06-09 16:14 ` Suzuki K Poulose
2025-06-09 16:43 ` Leo Yan
2025-06-09 16:00 ` [PATCH v3 6/9] coresight: Avoid enable programming clock duplicately Leo Yan
2025-06-09 16:58 ` Suzuki K Poulose
2025-06-09 17:14 ` Leo Yan
2025-06-10 10:39 ` Anshuman Khandual
2025-06-10 12:03 ` Leo Yan
2025-06-24 4:43 ` Anshuman Khandual
2025-06-24 5:11 ` Anshuman Khandual
2025-06-09 16:00 ` [PATCH v3 7/9] coresight: Consolidate clock enabling Leo Yan
2025-06-24 5:44 ` Anshuman Khandual
2025-06-24 10:08 ` Leo Yan
2025-06-09 16:00 ` [PATCH v3 8/9] coresight: Make clock sequence consistent Leo Yan
2025-06-09 16:00 ` [PATCH v3 9/9] coresight: Refactor runtime PM Leo Yan
2025-06-10 10:07 ` Anshuman Khandual [this message]
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