[v7,1/3] drm/bridge/synopsys: dsi: stop clobbering drvdata

Commit Message

Nickey Yang Dec. 12, 2017, 1:10 a.m. UTC

From: Brian Norris <[e-mail]>

Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
parent driver might need to own this. Instead, let's return our
'dw_mipi_dsi' object and have callers pass that back to us for removal.

Signed-off-by: Brian Norris <[e-mail]>
Signed-off-by: Nickey Yang <[e-mail]>
Link:https://patchwork.kernel.org/patch/10078493/

---
Changes

v4:
- Add From tag,update subject line
- keep patch "drm/stm: dsi: Adjust dw_mipi_dsi_probe and remove"
  in this piece together.

v5:
- remove Review & Ack tag
- fix remove() directly referencing the static
  dw_mipi_dsi_stm_plat_data struct.

v7:
- add missing platform_set_drvdata in stm part.

 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++-----------------
 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 12 ++++++---
 include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
 3 files changed, 32 insertions(+), 33 deletions(-)

Comments

Philippe CORNU Dec. 21, 2017, 2:59 p.m. UTC | #1

Hi Nickey,


On 12/12/2017 02:10 AM, Nickey Yang wrote:
> From: Brian Norris <[e-mail]>
> 
> Bridge drivers/helpers shouldn't be clobbering the drvdata, since a
> parent driver might need to own this. Instead, let's return our
> 'dw_mipi_dsi' object and have callers pass that back to us for removal.
> 
> Signed-off-by: Brian Norris <[e-mail]>
> Signed-off-by: Nickey Yang <[e-mail]>
> Link:https://patchwork.kernel.org/patch/10078493/
> 
> ---
> Changes
> 
> v4:
> - Add From tag,update subject line
> - keep patch "drm/stm: dsi: Adjust dw_mipi_dsi_probe and remove"
>    in this piece together.
> 
> v5:
> - remove Review & Ack tag
> - fix remove() directly referencing the static
>    dw_mipi_dsi_stm_plat_data struct.
> 
> v7:
> - add missing platform_set_drvdata in stm part.
> 
>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 36 ++++++++++-----------------
>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 12 ++++++---
>   include/drm/bridge/dw_mipi_dsi.h              | 17 ++++++++-----
>   3 files changed, 32 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index d9cca4f..c39c7dc 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -922,8 +922,6 @@ static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge)
>   	dsi->bridge.of_node = pdev->dev.of_node;
>   #endif
>   
> -	dev_set_drvdata(dev, dsi);
> -
>   	return dsi;
>   }
>   
> @@ -935,23 +933,16 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>   /*
>    * Probe/remove API, used from platforms based on the DRM bridge API.
>    */
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_probe(struct platform_device *pdev,
> +		  const struct dw_mipi_dsi_plat_data *plat_data)
>   {
> -	struct dw_mipi_dsi *dsi;
> -
> -	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
> -	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> -
> -	return 0;
> +	return __dw_mipi_dsi_probe(pdev, plat_data);
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>   
> -void dw_mipi_dsi_remove(struct platform_device *pdev)
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>   {
> -	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
> -
>   	mipi_dsi_host_unregister(&dsi->dsi_host);
>   
>   	__dw_mipi_dsi_remove(dsi);
> @@ -961,31 +952,30 @@ void dw_mipi_dsi_remove(struct platform_device *pdev)
>   /*
>    * Bind/unbind API, used from platforms based on the component framework.
>    */
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data)
> +struct dw_mipi_dsi *
> +dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> +		 const struct dw_mipi_dsi_plat_data *plat_data)
>   {
>   	struct dw_mipi_dsi *dsi;
>   	int ret;
>   
>   	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>   	if (IS_ERR(dsi))
> -		return PTR_ERR(dsi);
> +		return dsi;
>   
>   	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>   	if (ret) {
> -		dw_mipi_dsi_remove(pdev);
> +		dw_mipi_dsi_remove(dsi);
>   		DRM_ERROR("Failed to initialize bridge with drm\n");
> -		return ret;
> +		return ERR_PTR(ret);
>   	}
>   
> -	return 0;
> +	return dsi;
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>   
> -void dw_mipi_dsi_unbind(struct device *dev)
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
>   {
> -	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
> -
>   	__dw_mipi_dsi_remove(dsi);
>   }
>   EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index e5b6310..c1ed691 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -66,6 +66,7 @@ enum dsi_color {
>   struct dw_mipi_dsi_stm {
>   	void __iomem *base;
>   	struct clk *pllref_clk;
> +	struct dw_mipi_dsi *dmd;
>   };
>   
>   static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
> @@ -290,6 +291,8 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   	if (!dsi)
>   		return -ENOMEM;
>   
> +	platform_set_drvdata(pdev, dsi);
> +

Why don't you simply use the original patch from Brian.
With your last update, platform_set_drvdata() is called early during the 
stm_probe() and this is not the "classic" way: most of the time we 
prefer calling platform_set_drvdata() at the end of the probe (or as 
close as possible of the end of the probe). I took few minutes to look 
into drm directory and it seems to be the classic way for most of the 
drivers...

>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>   	if (!res) {
>   		DRM_ERROR("Unable to get resource\n");
> @@ -318,10 +321,11 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   	dw_mipi_dsi_stm_plat_data.base = dsi->base;
>   	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
>   
> -	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> -	if (ret) {
> +	dsi->dmd = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> +	if (IS_ERR(dsi->dmd)) {
>   		DRM_ERROR("Failed to initialize mipi dsi host\n");
>   		clk_disable_unprepare(dsi->pllref_clk);
> +		return PTR_ERR(dsi->dmd);
>   	}
>   
>   	return ret;

Moreover, I do prefer the "return 0;" from the Brian original version 
because "ret" here is far from its usage (from clk_prepare_enable()) 
with this new patch.

So, once again, I really prefer the Brian original version, on which you 
already got my Tested-By & Acked-by.

Is there any reason why you did not use the original patch?

Many thanks,
Philippe :-)
Note: I will be ooo next 2 weeks.

> @@ -329,10 +333,10 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
>   
>   static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>   {
> -	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> +	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>   
>   	clk_disable_unprepare(dsi->pllref_clk);
> -	dw_mipi_dsi_remove(pdev);
> +	dw_mipi_dsi_remove(dsi->dmd);
>   
>   	return 0;
>   }
> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
> index 9b30fec..d9c6d54 100644
> --- a/include/drm/bridge/dw_mipi_dsi.h
> +++ b/include/drm/bridge/dw_mipi_dsi.h
> @@ -10,6 +10,8 @@
>   #ifndef __DW_MIPI_DSI__
>   #define __DW_MIPI_DSI__
>   
> +struct dw_mipi_dsi;
> +
>   struct dw_mipi_dsi_phy_ops {
>   	int (*init)(void *priv_data);
>   	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
> @@ -29,11 +31,14 @@ struct dw_mipi_dsi_plat_data {
>   	void *priv_data;
>   };
>   
> -int dw_mipi_dsi_probe(struct platform_device *pdev,
> -		      const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_remove(struct platform_device *pdev);
> -int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		     const struct dw_mipi_dsi_plat_data *plat_data);
> -void dw_mipi_dsi_unbind(struct device *dev);
> +struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
> +				      const struct dw_mipi_dsi_plat_data
> +				      *plat_data);
> +void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
> +struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
> +				     struct drm_encoder *encoder,
> +				     const struct dw_mipi_dsi_plat_data
> +				     *plat_data);
> +void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
>   
>   #endif /* __DW_MIPI_DSI__ */
>

Patch

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index d9cca4f..c39c7dc 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -922,8 +922,6 @@  static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge)
 	dsi->bridge.of_node = pdev->dev.of_node;
 #endif
 
-	dev_set_drvdata(dev, dsi);
-
 	return dsi;
 }
 
@@ -935,23 +933,16 @@  static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
 /*
  * Probe/remove API, used from platforms based on the DRM bridge API.
  */
-int dw_mipi_dsi_probe(struct platform_device *pdev,
-		      const struct dw_mipi_dsi_plat_data *plat_data)
+struct dw_mipi_dsi *
+dw_mipi_dsi_probe(struct platform_device *pdev,
+		  const struct dw_mipi_dsi_plat_data *plat_data)
 {
-	struct dw_mipi_dsi *dsi;
-
-	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
-	if (IS_ERR(dsi))
-		return PTR_ERR(dsi);
-
-	return 0;
+	return __dw_mipi_dsi_probe(pdev, plat_data);
 }
 EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
 
-void dw_mipi_dsi_remove(struct platform_device *pdev)
+void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
 {
-	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
-
 	mipi_dsi_host_unregister(&dsi->dsi_host);
 
 	__dw_mipi_dsi_remove(dsi);
@@ -961,31 +952,30 @@  void dw_mipi_dsi_remove(struct platform_device *pdev)
 /*
  * Bind/unbind API, used from platforms based on the component framework.
  */
-int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
-		     const struct dw_mipi_dsi_plat_data *plat_data)
+struct dw_mipi_dsi *
+dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
+		 const struct dw_mipi_dsi_plat_data *plat_data)
 {
 	struct dw_mipi_dsi *dsi;
 	int ret;
 
 	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
 	if (IS_ERR(dsi))
-		return PTR_ERR(dsi);
+		return dsi;
 
 	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
 	if (ret) {
-		dw_mipi_dsi_remove(pdev);
+		dw_mipi_dsi_remove(dsi);
 		DRM_ERROR("Failed to initialize bridge with drm\n");
-		return ret;
+		return ERR_PTR(ret);
 	}
 
-	return 0;
+	return dsi;
 }
 EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
 
-void dw_mipi_dsi_unbind(struct device *dev)
+void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
 {
-	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
-
 	__dw_mipi_dsi_remove(dsi);
 }
 EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index e5b6310..c1ed691 100644
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -66,6 +66,7 @@  enum dsi_color {
 struct dw_mipi_dsi_stm {
 	void __iomem *base;
 	struct clk *pllref_clk;
+	struct dw_mipi_dsi *dmd;
 };
 
 static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
@@ -290,6 +291,8 @@  static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 	if (!dsi)
 		return -ENOMEM;
 
+	platform_set_drvdata(pdev, dsi);
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		DRM_ERROR("Unable to get resource\n");
@@ -318,10 +321,11 @@  static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 	dw_mipi_dsi_stm_plat_data.base = dsi->base;
 	dw_mipi_dsi_stm_plat_data.priv_data = dsi;
 
-	ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
-	if (ret) {
+	dsi->dmd = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
+	if (IS_ERR(dsi->dmd)) {
 		DRM_ERROR("Failed to initialize mipi dsi host\n");
 		clk_disable_unprepare(dsi->pllref_clk);
+		return PTR_ERR(dsi->dmd);
 	}
 
 	return ret;
@@ -329,10 +333,10 @@  static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 
 static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
 {
-	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
+	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
 
 	clk_disable_unprepare(dsi->pllref_clk);
-	dw_mipi_dsi_remove(pdev);
+	dw_mipi_dsi_remove(dsi->dmd);
 
 	return 0;
 }
diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
index 9b30fec..d9c6d54 100644
--- a/include/drm/bridge/dw_mipi_dsi.h
+++ b/include/drm/bridge/dw_mipi_dsi.h
@@ -10,6 +10,8 @@ 
 #ifndef __DW_MIPI_DSI__
 #define __DW_MIPI_DSI__
 
+struct dw_mipi_dsi;
+
 struct dw_mipi_dsi_phy_ops {
 	int (*init)(void *priv_data);
 	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
@@ -29,11 +31,14 @@  struct dw_mipi_dsi_plat_data {
 	void *priv_data;
 };
 
-int dw_mipi_dsi_probe(struct platform_device *pdev,
-		      const struct dw_mipi_dsi_plat_data *plat_data);
-void dw_mipi_dsi_remove(struct platform_device *pdev);
-int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
-		     const struct dw_mipi_dsi_plat_data *plat_data);
-void dw_mipi_dsi_unbind(struct device *dev);
+struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev,
+				      const struct dw_mipi_dsi_plat_data
+				      *plat_data);
+void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi);
+struct dw_mipi_dsi *dw_mipi_dsi_bind(struct platform_device *pdev,
+				     struct drm_encoder *encoder,
+				     const struct dw_mipi_dsi_plat_data
+				     *plat_data);
+void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi);
 
 #endif /* __DW_MIPI_DSI__ */