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

Hi Nickey,

On 12/12/2017 02:10 AM, Nickey Yang wrote:

From: Brian Norris briannorris@chromium.org

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 briannorris@chromium.org Signed-off-by: Nickey Yang nickey.yang@rock-chips.com 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__ */