Re: [PATCH v5 6/8] media: mtk-mdp: propagate errors better in pm_suspend/resume

From: Enric Balletbo i Serra
Date: Mon Jul 12 2021 - 06:13:09 EST


Hi Eizan,

Thank you for your patch.

On 9/7/21 4:23, Eizan Miyamoto wrote:
> Up until this change, many errors were logged but ignored when powering
> on clocks and calling pm_runtime_get/put() inside mtk_mdp_core. This
> change tries to do a better job at propagating errors back to the power
> management framework.
>

Yeah, that's nice. I commented that i dislike the error handling and seems that
you're fixing part of it here. It was a bit difficult to review the patches
because this back and forth, some problems introduced by previous patches where
fixed later. If possible I'd reorganize a bit the patches, even squash some of
the pm changes. Basically move this patch before, and do it together with the
other pm patches (even try to squash if possible).


> Signed-off-by: Eizan Miyamoto <eizan@xxxxxxxxxxxx>
> ---
>
> (no changes since v1)
>
> drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 62 ++++++++++++++++---
> drivers/media/platform/mtk-mdp/mtk_mdp_comp.h | 6 +-
> drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 57 +++++++++++++----
> 3 files changed, 99 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> index 8a9267d0da1e..87e3f72ff02b 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> @@ -53,9 +53,9 @@ static const struct of_device_id mtk_mdp_comp_driver_dt_match[] = {
> };
> MODULE_DEVICE_TABLE(of, mtk_mdp_comp_driver_dt_match);
>
> -void mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp)
> +int mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp)
> {
> - int err;
> + int status, err;
>
> if (comp->larb_dev) {
> err = mtk_smi_larb_get(comp->larb_dev);
> @@ -65,34 +65,76 @@ void mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp)
> }
>
> err = pm_runtime_get_sync(comp->dev);
> - if (err < 0)
> + if (err < 0) {
> dev_err(comp->dev, "failed to runtime get, err %d.\n", err);
> + return err;
> + }
> +
> + err = mtk_mdp_comp_clock_on(comp);
> + if (err) {
> + dev_err(comp->dev, "failed to turn on clock. err=%d", err);
> + status = err;
> + goto err_mtk_mdp_comp_clock_on;
> + }
> +
> + return err;
> +
> +err_mtk_mdp_comp_clock_on:
> + err = pm_runtime_put_sync(comp->dev);
> + if (err)
> + dev_err(comp->dev, "failed to runtime put in cleanup. err=%d", err);
>
> - mtk_mdp_comp_clock_on(comp);
> + return status;
> }
>
> -void mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp)
> +int mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp)
> {
> - int err;
> + int status, err;
>
> mtk_mdp_comp_clock_off(comp);
>
> err = pm_runtime_put_sync(comp->dev);
> - if (err < 0)
> + if (err < 0) {
> dev_err(comp->dev, "failed to runtime put, err %d.\n", err);
> + status = err;
> + goto err_pm_runtime_put_sync;
> + }
> +
> + return 0;
> +
> +err_pm_runtime_put_sync:
> + err = mtk_mdp_comp_clock_on(comp);
> + if (err)
> + dev_err(comp->dev, "failed to turn on clock in cleanup. err=%d", err);
> +
> + return status;
> }
>
> -void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp)
> +int mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp)
> {
> - int i, err;
> + int i, err, status;
>
> for (i = 0; i < ARRAY_SIZE(comp->clk); i++) {
> if (IS_ERR(comp->clk[i]))
> continue;
> err = clk_prepare_enable(comp->clk[i]);
> - if (err)
> + if (err) {
> + status = err;
> dev_err(comp->dev, "failed to enable clock, err %d. i:%d\n", err, i);
> + goto err_clk_prepare_enable;
> + }
> + }
> +
> + return 0;
> +
> +err_clk_prepare_enable:
> + for (--i; i >= 0; i--) {
> + if (IS_ERR(comp->clk[i]))
> + continue;
> + clk_disable_unprepare(comp->clk[i]);
> }
> +
> + return status;
> }
>
> void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp)
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h
> index 15ef9539a5a7..5201c47f7baa 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h
> @@ -23,10 +23,10 @@ struct mtk_mdp_comp {
>
> int mtk_mdp_comp_init(struct mtk_mdp_comp *comp, struct device *dev);
>
> -void mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp);
> -void mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp);
> +int mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp);
> +int mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp);
>
> -void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp);
> +int mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp);
> void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp);
>
> extern struct platform_driver mtk_mdp_component_driver;
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> index 74ef37eb50bd..b45d588d2659 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> @@ -50,8 +50,9 @@ static const struct of_device_id mtk_mdp_of_ids[] = {
> };
> MODULE_DEVICE_TABLE(of, mtk_mdp_of_ids);
>
> -static void mtk_mdp_clock_on(struct mtk_mdp_dev *mdp)
> +static int mtk_mdp_clock_on(struct mtk_mdp_dev *mdp)
> {
> + int err, status;
> struct mtk_mdp_comp *comp_node;
>
> /*
> @@ -59,18 +60,41 @@ static void mtk_mdp_clock_on(struct mtk_mdp_dev *mdp)
> * on it through mtk_mdp_m2m_start_streaming, making it unnecessary to
> * have mtk_mdp_comp_power_on called on it.
> */
> - mtk_mdp_comp_clock_on(&mdp->comp_self);
> + err = mtk_mdp_comp_clock_on(&mdp->comp_self);
> + if (err)
> + return err;
> +
> + list_for_each_entry(comp_node, &mdp->comp_list, node) {
> + err = mtk_mdp_comp_power_on(comp_node);
> + if (err) {
> + status = err;
> + goto err_mtk_mdp_comp_power_on;
> + }
> + }
>
> - list_for_each_entry(comp_node, &mdp->comp_list, node)
> - mtk_mdp_comp_power_on(comp_node);
> + return 0;
> +
> +err_mtk_mdp_comp_power_on:
> + list_for_each_entry_continue_reverse(comp_node, &mdp->comp_list, node) {
> + err = mtk_mdp_comp_power_off(comp_node);
> + if (err)
> + dev_err(&mdp->pdev->dev, "failed to power off after error. err=%d", err);
> + }
> + return status;
> }
>
> -static void mtk_mdp_clock_off(struct mtk_mdp_dev *mdp)
> +static int mtk_mdp_clock_off(struct mtk_mdp_dev *mdp)
> {
> + int status, err;
> struct mtk_mdp_comp *comp_node;
>
> - list_for_each_entry(comp_node, &mdp->comp_list, node)
> - mtk_mdp_comp_power_off(comp_node);
> + list_for_each_entry(comp_node, &mdp->comp_list, node) {
> + err = mtk_mdp_comp_power_off(comp_node);
> + if (err) {
> + status = err;
> + goto err_mtk_mdp_comp_power_off;
> + }
> + }
>
> /*
> * The master / rdma0 component will have pm_runtime_put called
> @@ -78,6 +102,17 @@ static void mtk_mdp_clock_off(struct mtk_mdp_dev *mdp)
> * have mtk_mdp_comp_power_off called on it.
> */
> mtk_mdp_comp_clock_off(&mdp->comp_self);
> +
> + return 0;
> +
> +err_mtk_mdp_comp_power_off:
> + list_for_each_entry_continue_reverse(comp_node, &mdp->comp_list, node) {
> + err = mtk_mdp_comp_power_on(comp_node);
> + if (err)
> + dev_err(&mdp->pdev->dev, "failed to power on after error. err=%d", err);
> + }
> +
> + return status;
> }
>
> static void mtk_mdp_wdt_worker(struct work_struct *work)
> @@ -318,18 +353,14 @@ static int __maybe_unused mtk_mdp_pm_suspend(struct device *dev)
> {
> struct mtk_mdp_dev *mdp = dev_get_drvdata(dev);
>
> - mtk_mdp_clock_off(mdp);
> -
> - return 0;
> + return mtk_mdp_clock_off(mdp);
> }
>
> static int __maybe_unused mtk_mdp_pm_resume(struct device *dev)
> {
> struct mtk_mdp_dev *mdp = dev_get_drvdata(dev);
>
> - mtk_mdp_clock_on(mdp);
> -
> - return 0;
> + return mtk_mdp_clock_on(mdp);
> }
>
> static int __maybe_unused mtk_mdp_suspend(struct device *dev)
>