Re: [PATCH RESEND v3 2/3] drm/stm: dsi: add pm runtime ops

[Yannick FERTRE <yannick.fertre@xxxxxxxxxxx>]

Hi Raphael,

thanks for the patch.

Acked-by: Yannick Fertre <yannick.fertre@xxxxxxxxxxx>

Tested-by: Yannick Fertre <yannick.fertre@xxxxxxxxxxx>

BR


Le 29/01/2024 à 11:41, Raphael Gallais-Pou a écrit :
> From: Yannick Fertre <yannick.fertre@xxxxxxxxxxx>
>
> Update control of clocks and supply thanks to the PM runtime
> mechanism to avoid kernel crash during a system suspend.
>
> Signed-off-by: Yannick Fertre <yannick.fertre@xxxxxxxxxxx>
> Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@xxxxxxxxxxx>
> ---
> Changes in v2:
> 	- Changed SET_RUNTIME_PM_OPS to RUNTIME_PM_OPS and removed
> 	__maybe_unused
> ---
>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 24 ++++++++++++++++++------
>   1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index b1aee43d51e9..82fff9e84345 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -11,6 +11,7 @@
>   #include <linux/mod_devicetable.h>
>   #include <linux/module.h>
>   #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>   #include <linux/regulator/consumer.h>
>   
>   #include <video/mipi_display.h>
> @@ -77,6 +78,7 @@ enum dsi_color {
>   struct dw_mipi_dsi_stm {
>   	void __iomem *base;
>   	struct clk *pllref_clk;
> +	struct clk *pclk;
>   	struct dw_mipi_dsi *dsi;
>   	u32 hw_version;
>   	int lane_min_kbps;
> @@ -443,7 +445,6 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
>   	struct dw_mipi_dsi_stm *dsi;
> -	struct clk *pclk;
>   	int ret;
>   
>   	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> @@ -483,21 +484,21 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   		goto err_clk_get;
>   	}
>   
> -	pclk = devm_clk_get(dev, "pclk");
> -	if (IS_ERR(pclk)) {
> -		ret = PTR_ERR(pclk);
> +	dsi->pclk = devm_clk_get(dev, "pclk");
> +	if (IS_ERR(dsi->pclk)) {
> +		ret = PTR_ERR(dsi->pclk);
>   		DRM_ERROR("Unable to get peripheral clock: %d\n", ret);
>   		goto err_dsi_probe;
>   	}
>   
> -	ret = clk_prepare_enable(pclk);
> +	ret = clk_prepare_enable(dsi->pclk);
>   	if (ret) {
>   		DRM_ERROR("%s: Failed to enable peripheral clk\n", __func__);
>   		goto err_dsi_probe;
>   	}
>   
>   	dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
> -	clk_disable_unprepare(pclk);
> +	clk_disable_unprepare(dsi->pclk);
>   
>   	if (dsi->hw_version != HWVER_130 && dsi->hw_version != HWVER_131) {
>   		ret = -ENODEV;
> @@ -551,6 +552,7 @@ static int dw_mipi_dsi_stm_suspend(struct device *dev)
>   	DRM_DEBUG_DRIVER("\n");
>   
>   	clk_disable_unprepare(dsi->pllref_clk);
> +	clk_disable_unprepare(dsi->pclk);
>   	regulator_disable(dsi->vdd_supply);
>   
>   	return 0;
> @@ -569,8 +571,16 @@ static int dw_mipi_dsi_stm_resume(struct device *dev)
>   		return ret;
>   	}
>   
> +	ret = clk_prepare_enable(dsi->pclk);
> +	if (ret) {
> +		regulator_disable(dsi->vdd_supply);
> +		DRM_ERROR("Failed to enable pclk: %d\n", ret);
> +		return ret;
> +	}
> +
>   	ret = clk_prepare_enable(dsi->pllref_clk);
>   	if (ret) {
> +		clk_disable_unprepare(dsi->pclk);
>   		regulator_disable(dsi->vdd_supply);
>   		DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
>   		return ret;
> @@ -582,6 +592,8 @@ static int dw_mipi_dsi_stm_resume(struct device *dev)
>   static const struct dev_pm_ops dw_mipi_dsi_stm_pm_ops = {
>   	SYSTEM_SLEEP_PM_OPS(dw_mipi_dsi_stm_suspend,
>   			    dw_mipi_dsi_stm_resume)
> +	RUNTIME_PM_OPS(dw_mipi_dsi_stm_suspend,
> +		       dw_mipi_dsi_stm_resume, NULL)
>   };
>   
>   static struct platform_driver dw_mipi_dsi_stm_driver = {