On Mon, 18 May 2020 19:39:07 +0200 Enric Balletbo i Serra enric.balletbo@collabora.com wrote:

This is really a cosmetic change just to make a bit more readable the code after convert the driver to drm_bridge. The bridge variable name will be used by the encoder drm_bridge, and the chained bridge will be named next_bridge.

Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Reviewed-by: Chun-Kuang Hu chunkuang.hu@kernel.org

---

drivers/gpu/drm/mediatek/mtk_dpi.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index 7fbfa95bab09..7112125dc3d1 100644 --- a/drivers/gpu/drm/mediatek/mtk_dpi.c +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c @@ -61,7 +61,7 @@ enum mtk_dpi_out_color_format { struct mtk_dpi { struct mtk_ddp_comp ddp_comp; struct drm_encoder encoder;

• struct drm_bridge *bridge;

• struct drm_bridge *next_bridge;

Did you consider moving the drm_of_find_panel_or_bridge() call to mtk_dpi_bind() so you can get rid of this field?

This makes we realize there's no refcounting on bridges, which means the bridge can vanish between the drm_of_find_panel_or_bridge() and drm_bridge_attach() calls :-/.

void __iomem *regs; struct device *dev; struct clk *engine_clk; @@ -607,7 +607,7 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data) /* Currently DPI0 is fixed to be driven by OVL1 */ dpi->encoder.possible_crtcs = BIT(1);

• ret = drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL, 0);

• ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0); if (ret) { dev_err(dev, "Failed to attach bridge: %d\n", ret); goto err_cleanup;

@@ -747,11 +747,11 @@ static int mtk_dpi_probe(struct platform_device *pdev) }

ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,

• 			  NULL, &dpi->bridge);
  

• 			  NULL, &dpi->next_bridge);
  

  if (ret) return ret;

• dev_info(dev, "Found bridge node: %pOF\n", dpi->bridge->of_node);

• dev_info(dev, "Found bridge node: %pOF\n", dpi->next_bridge->of_node);

  comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI); if (comp_id < 0) {

Hi Boris,

Thank you for review the patch.

On 1/7/20 13:51, Boris Brezillon wrote:

On Mon, 18 May 2020 19:39:08 +0200 Enric Balletbo i Serra enric.balletbo@collabora.com wrote:

...

Convert mtk_dpi to a bridge driver with built-in encoder support for compatibility with existing component drivers.

Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Reviewed-by: Chun-Kuang Hu chunkuang.hu@kernel.org

---

drivers/gpu/drm/mediatek/mtk_dpi.c | 66 +++++++++++++++--------------- 1 file changed, 34 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index 7112125dc3d1..baad198c69eb 100644 --- a/drivers/gpu/drm/mediatek/mtk_dpi.c +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c @@ -61,6 +61,7 @@ enum mtk_dpi_out_color_format { struct mtk_dpi { struct mtk_ddp_comp ddp_comp; struct drm_encoder encoder;

• struct drm_bridge bridge; struct drm_bridge *next_bridge; void __iomem *regs; struct device *dev;

@@ -77,9 +78,9 @@ struct mtk_dpi { int refcount; };

-static inline struct mtk_dpi *mtk_dpi_from_encoder(struct drm_encoder *e) +static inline struct mtk_dpi *bridge_to_dpi(struct drm_bridge *b) {

• return container_of(e, struct mtk_dpi, encoder);

• return container_of(b, struct mtk_dpi, bridge);

}

enum mtk_dpi_polarity { @@ -518,50 +519,44 @@ static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = { .destroy = mtk_dpi_encoder_destroy, };

-static bool mtk_dpi_encoder_mode_fixup(struct drm_encoder *encoder,

• 		       const struct drm_display_mode *mode,
  

• 		       struct drm_display_mode *adjusted_mode)
  

+static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,

• 		 enum drm_bridge_attach_flags flags)
  

{

• return true;

• struct mtk_dpi *dpi = bridge_to_dpi(bridge);
• return drm_bridge_attach(bridge->encoder, dpi->next_bridge,

• 		 &dpi->bridge, flags);
  

}

-static void mtk_dpi_encoder_mode_set(struct drm_encoder *encoder,

• 		     struct drm_display_mode *mode,
  

• 		     struct drm_display_mode *adjusted_mode)
  

+static void mtk_dpi_bridge_mode_set(struct drm_bridge *bridge,

• 		const struct drm_display_mode *mode,
  

• 		const struct drm_display_mode *adjusted_mode)
  

{

• struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);

• struct mtk_dpi *dpi = bridge_to_dpi(bridge);

  drm_mode_copy(&dpi->mode, adjusted_mode);

}

-static void mtk_dpi_encoder_disable(struct drm_encoder *encoder) +static void mtk_dpi_bridge_disable(struct drm_bridge *bridge) {

• struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);

• struct mtk_dpi *dpi = bridge_to_dpi(bridge);

  mtk_dpi_power_off(dpi);

}

-static void mtk_dpi_encoder_enable(struct drm_encoder *encoder) +static void mtk_dpi_bridge_enable(struct drm_bridge *bridge) {

• struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);

• struct mtk_dpi *dpi = bridge_to_dpi(bridge);

  mtk_dpi_power_on(dpi); mtk_dpi_set_display_mode(dpi, &dpi->mode);

}

-static int mtk_dpi_atomic_check(struct drm_encoder *encoder,

• 		struct drm_crtc_state *crtc_state,
  

• 		struct drm_connector_state *conn_state)
  

-{

• return 0;

-}

-static const struct drm_encoder_helper_funcs mtk_dpi_encoder_helper_funcs = {

• .mode_fixup = mtk_dpi_encoder_mode_fixup,
• .mode_set = mtk_dpi_encoder_mode_set,
• .disable = mtk_dpi_encoder_disable,
• .enable = mtk_dpi_encoder_enable,
• .atomic_check = mtk_dpi_atomic_check,

+static const struct drm_bridge_funcs mtk_dpi_bridge_funcs = {

• .attach = mtk_dpi_bridge_attach,
• .mode_set = mtk_dpi_bridge_mode_set,
• .disable = mtk_dpi_bridge_disable,
• .enable = mtk_dpi_bridge_enable,

};

static void mtk_dpi_start(struct mtk_ddp_comp *comp) @@ -602,16 +597,13 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data) dev_err(dev, "Failed to initialize decoder: %d\n", ret); goto err_unregister; }

• drm_encoder_helper_add(&dpi->encoder, &mtk_dpi_encoder_helper_funcs);

  /* Currently DPI0 is fixed to be driven by OVL1 */ dpi->encoder.possible_crtcs = BIT(1);

• ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);

• if (ret) {

• dev_err(dev, "Failed to attach bridge: %d\n", ret);
  

Any reason your decided to drop this error message? If there's one, this should probably happen in a separate patch.

Right, I'll maintain the error in next version.

...

• ret = drm_bridge_attach(&dpi->encoder, &dpi->bridge, NULL, 0);
• if (ret) goto err_cleanup;

• }

  dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS; dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;

@@ -768,8 +760,15 @@ static int mtk_dpi_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, dpi);

• dpi->bridge.funcs = &mtk_dpi_bridge_funcs;
• dpi->bridge.of_node = dev->of_node;
• dpi->bridge.type = DRM_MODE_CONNECTOR_DPI;
• drm_bridge_add(&dpi->bridge);

I wonder if it's really useful to add the bridge when it's private (you don't want this bridge to be added to external bridge chains).

...

• ret = component_add(dev, &mtk_dpi_component_ops); if (ret) {

• drm_bridge_remove(&dpi->bridge);
  

  dev_err(dev, "Failed to add component: %d\n", ret); return ret; }

@@ -779,7 +778,10 @@ static int mtk_dpi_probe(struct platform_device *pdev)

static int mtk_dpi_remove(struct platform_device *pdev) {

• struct mtk_dpi *dpi = platform_get_drvdata(pdev);

• component_del(&pdev->dev, &mtk_dpi_component_ops);

• drm_bridge_remove(&dpi->bridge);

  return 0;

}

On Mon, 18 May 2020 19:39:09 +0200 Enric Balletbo i Serra enric.balletbo@collabora.com wrote:

The mtk_dpi driver uses an empty implementation for its encoder. Replace the code with the generic simple encoder.

Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Reviewed-by: Chun-Kuang Hu chunkuang.hu@kernel.org

---

drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index baad198c69eb..80778b2aac2a 100644 --- a/drivers/gpu/drm/mediatek/mtk_dpi.c +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c @@ -20,6 +20,7 @@ #include <drm/drm_bridge.h> #include <drm/drm_crtc.h> #include <drm/drm_of.h> +#include <drm/drm_simple_kms_helper.h>

#include "mtk_dpi_regs.h" #include "mtk_drm_ddp_comp.h" @@ -510,15 +511,6 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi, return 0; }

-static void mtk_dpi_encoder_destroy(struct drm_encoder *encoder) -{

• drm_encoder_cleanup(encoder);

-}

-static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {

• .destroy = mtk_dpi_encoder_destroy,

-};

static int mtk_dpi_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags) { @@ -591,8 +583,8 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data) return ret; }

• ret = drm_encoder_init(drm_dev, &dpi->encoder, &mtk_dpi_encoder_funcs,

• 	       DRM_MODE_ENCODER_TMDS, NULL);
  

• ret = drm_simple_encoder_init(drm_dev, &dpi->encoder,

• 		      DRM_MODE_ENCODER_TMDS);
  

Not related to this change, but shouldn't we have DRM_MODE_ENCODER_DPI here?

if (ret) { dev_err(dev, "Failed to initialize decoder: %d\n", ret); goto err_unregister;

Hi again,

On 8/7/20 17:12, Enric Balletbo i Serra wrote:

Hi Boris,

Thank you to spend some time to review the patches.

On 1/7/20 13:41, Boris Brezillon wrote:

...

On Mon, 18 May 2020 19:39:09 +0200 Enric Balletbo i Serra enric.balletbo@collabora.com wrote:

...

The mtk_dpi driver uses an empty implementation for its encoder. Replace the code with the generic simple encoder.

Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Reviewed-by: Chun-Kuang Hu chunkuang.hu@kernel.org

---

drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index baad198c69eb..80778b2aac2a 100644 --- a/drivers/gpu/drm/mediatek/mtk_dpi.c +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c @@ -20,6 +20,7 @@ #include <drm/drm_bridge.h> #include <drm/drm_crtc.h> #include <drm/drm_of.h> +#include <drm/drm_simple_kms_helper.h>

#include "mtk_dpi_regs.h" #include "mtk_drm_ddp_comp.h" @@ -510,15 +511,6 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi, return 0; }

-static void mtk_dpi_encoder_destroy(struct drm_encoder *encoder) -{

• drm_encoder_cleanup(encoder);

-}

-static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {

• .destroy = mtk_dpi_encoder_destroy,

-};

static int mtk_dpi_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags) { @@ -591,8 +583,8 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data) return ret; }

• ret = drm_encoder_init(drm_dev, &dpi->encoder, &mtk_dpi_encoder_funcs,

• 	       DRM_MODE_ENCODER_TMDS, NULL);
  

• ret = drm_simple_encoder_init(drm_dev, &dpi->encoder,

• 		      DRM_MODE_ENCODER_TMDS);
  

Not related to this change, but shouldn't we have DRM_MODE_ENCODER_DPI here?

Thinking a bit more about this and this patchset in general, I think I'll drop this patch from the series, at the end, all the encoder creation stuff should be moved to mtk_drm_drv.

Right, I'll add a patch to fix this.

...

...

if (ret) { dev_err(dev, "Failed to initialize decoder: %d\n", ret); goto err_unregister;