[PATCH v3 1/4] drm/rockchip: dsi: Hold pm-runtime across bind/unbind

[PATCH v3 1/4] drm/rockchip: dsi: Hold pm-runtime across bind/unbind

[Brian Norris]

In commit 43c2de1002d2, we moved most HW configuration to bind(), but we
didn't move the runtime PM management. Therefore, depending on initial
boot state, runtime-PM workqueue delays, and other timing factors, we
may disable our power domain in between the hardware configuration
(bind()) and when we enable the display. This can cause us to lose
hardware state and fail to configure our display. For example:

  dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
  panel-innolux-p079zca ff960000.mipi.0: failed to write command 0

or:

  dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
  panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110

We should match the runtime PM to the lifetime of the bind()/unbind()
cycle.

Tested on Acer Chrometab 10 (RK3399 Gru-Scarlet), with panel drivers
built either as modules or built-in.

Side notes: it seems one is more likely to see this problem when the
panel driver is built into the kernel. I've also seen this problem
bisect down to commits that simply changed Kconfig dependencies, because
it changed the order in which driver init functions were compiled into
the kernel, and therefore the ordering and timing of built-in device
probe.

Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
Link: https://lore.kernel.org/linux-rockchip/9aedfb528600ecf871885f7293ca4207c84d16c1.camel@gmail.com/
Reported-by: <aleksandr.o.makarov@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
---

(no changes since v2)

Changes in v2:
- Clean up pm-runtime state in error cases.
- Correct git hash for Fixes.

 .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c   | 37 ++++++++++---------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
index a2262bee5aa4..45676b23c019 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
@@ -773,10 +773,6 @@ static void dw_mipi_dsi_encoder_enable(struct drm_encoder *encoder)
 	if (mux < 0)
 		return;
 
-	pm_runtime_get_sync(dsi->dev);
-	if (dsi->slave)
-		pm_runtime_get_sync(dsi->slave->dev);
-
 	/*
 	 * For the RK3399, the clk of grf must be enabled before writing grf
 	 * register. And for RK3288 or other soc, this grf_clk must be NULL,
@@ -795,20 +791,10 @@ static void dw_mipi_dsi_encoder_enable(struct drm_encoder *encoder)
 	clk_disable_unprepare(dsi->grf_clk);
 }
 
-static void dw_mipi_dsi_encoder_disable(struct drm_encoder *encoder)
-{
-	struct dw_mipi_dsi_rockchip *dsi = to_dsi(encoder);
-
-	if (dsi->slave)
-		pm_runtime_put(dsi->slave->dev);
-	pm_runtime_put(dsi->dev);
-}
-
 static const struct drm_encoder_helper_funcs
 dw_mipi_dsi_encoder_helper_funcs = {
 	.atomic_check = dw_mipi_dsi_encoder_atomic_check,
 	.enable = dw_mipi_dsi_encoder_enable,
-	.disable = dw_mipi_dsi_encoder_disable,
 };
 
 static int rockchip_dsi_drm_create_encoder(struct dw_mipi_dsi_rockchip *dsi,
@@ -938,10 +924,14 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev,
 		put_device(second);
 	}
 
+	pm_runtime_get_sync(dsi->dev);
+	if (dsi->slave)
+		pm_runtime_get_sync(dsi->slave->dev);
+
 	ret = clk_prepare_enable(dsi->pllref_clk);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "Failed to enable pllref_clk: %d\n", ret);
-		return ret;
+		goto out_pm_runtime;
 	}
 
 	/*
@@ -953,7 +943,7 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev,
 	ret = clk_prepare_enable(dsi->grf_clk);
 	if (ret) {
 		DRM_DEV_ERROR(dsi->dev, "Failed to enable grf_clk: %d\n", ret);
-		return ret;
+		goto out_pm_runtime;
 	}
 
 	dw_mipi_dsi_rockchip_config(dsi);
@@ -965,16 +955,23 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev,
 	ret = rockchip_dsi_drm_create_encoder(dsi, drm_dev);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "Failed to create drm encoder\n");
-		return ret;
+		goto out_pm_runtime;
 	}
 
 	ret = dw_mipi_dsi_bind(dsi->dmd, &dsi->encoder);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "Failed to bind: %d\n", ret);
-		return ret;
+		goto out_pm_runtime;
 	}
 
 	return 0;
+
+out_pm_runtime:
+	pm_runtime_put(dsi->dev);
+	if (dsi->slave)
+		pm_runtime_put(dsi->slave->dev);
+
+	return ret;
 }
 
 static void dw_mipi_dsi_rockchip_unbind(struct device *dev,
@@ -989,6 +986,10 @@ static void dw_mipi_dsi_rockchip_unbind(struct device *dev,
 	dw_mipi_dsi_unbind(dsi->dmd);
 
 	clk_disable_unprepare(dsi->pllref_clk);
+
+	pm_runtime_put(dsi->dev);
+	if (dsi->slave)
+		pm_runtime_put(dsi->slave->dev);
 }
 
 static const struct component_ops dw_mipi_dsi_rockchip_ops = {
-- 
2.33.0.685.g46640cef36-goog

Re: [PATCH v3 1/4] drm/rockchip: dsi: Hold pm-runtime across bind/unbind

[Chen-Yu Tsai]

On Wed, Sep 29, 2021 at 5:36 AM Brian Norris <briannorris@chromium.org> wrote:
>
> In commit 43c2de1002d2, we moved most HW configuration to bind(), but we
> didn't move the runtime PM management. Therefore, depending on initial
> boot state, runtime-PM workqueue delays, and other timing factors, we
> may disable our power domain in between the hardware configuration
> (bind()) and when we enable the display. This can cause us to lose
> hardware state and fail to configure our display. For example:
>
>   dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
>   panel-innolux-p079zca ff960000.mipi.0: failed to write command 0
>
> or:
>
>   dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
>   panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110
>
> We should match the runtime PM to the lifetime of the bind()/unbind()
> cycle.
>
> Tested on Acer Chrometab 10 (RK3399 Gru-Scarlet), with panel drivers
> built either as modules or built-in.
>
> Side notes: it seems one is more likely to see this problem when the
> panel driver is built into the kernel. I've also seen this problem
> bisect down to commits that simply changed Kconfig dependencies, because
> it changed the order in which driver init functions were compiled into
> the kernel, and therefore the ordering and timing of built-in device
> probe.
>
> Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
> Link: https://lore.kernel.org/linux-rockchip/9aedfb528600ecf871885f7293ca4207c84d16c1.camel@gmail.com/
> Reported-by: <aleksandr.o.makarov@gmail.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

[PATCH v3 2/4] drm/rockchip: dsi: Reconfigure hardware on resume()

[Brian Norris]

Since commit 43c2de1002d2, we perform most HW configuration in the
bind() function. This configuration may be lost on suspend/resume, so we
need to call it again. That may lead to errors like this after system
suspend/resume:

  dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
  panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110

Tested on Acer Chromebook Tab 10 (RK3399 Gru-Scarlet).

Note that early mailing list versions of this driver borrowed Rockchip's
downstream/BSP solution, to do HW configuration in mode_set() (which
*is* called at the appropriate pre-enable() times), but that was
discarded along the way. I've avoided that still, because mode_set()
documentation doesn't suggest this kind of purpose as far as I can tell.

Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
---

Changes in v3:
 - New patch, to fix related PM issue discovered after patch 1

 .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c   | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
index 45676b23c019..21c67343cc6c 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
@@ -268,6 +268,8 @@ struct dw_mipi_dsi_rockchip {
 	struct dw_mipi_dsi *dmd;
 	const struct rockchip_dw_dsi_chip_data *cdata;
 	struct dw_mipi_dsi_plat_data pdata;
+
+	bool dsi_bound;
 };
 
 struct dphy_pll_parameter_map {
@@ -964,6 +966,8 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev,
 		goto out_pm_runtime;
 	}
 
+	dsi->dsi_bound = true;
+
 	return 0;
 
 out_pm_runtime:
@@ -983,6 +987,8 @@ static void dw_mipi_dsi_rockchip_unbind(struct device *dev,
 	if (dsi->is_slave)
 		return;
 
+	dsi->dsi_bound = false;
+
 	dw_mipi_dsi_unbind(dsi->dmd);
 
 	clk_disable_unprepare(dsi->pllref_clk);
@@ -1277,6 +1283,36 @@ static const struct phy_ops dw_mipi_dsi_dphy_ops = {
 	.exit		= dw_mipi_dsi_dphy_exit,
 };
 
+static int __maybe_unused dw_mipi_dsi_rockchip_resume(struct device *dev)
+{
+	struct dw_mipi_dsi_rockchip *dsi = dev_get_drvdata(dev);
+	int ret;
+
+	/*
+	 * Re-configure DSI state, if we were previously initialized. We need
+	 * to do this before rockchip_drm_drv tries to re-enable() any panels.
+	 */
+	if (dsi->dsi_bound) {
+		ret = clk_prepare_enable(dsi->grf_clk);
+		if (ret) {
+			DRM_DEV_ERROR(dsi->dev, "Failed to enable grf_clk: %d\n", ret);
+			return ret;
+		}
+
+		dw_mipi_dsi_rockchip_config(dsi);
+		if (dsi->slave)
+			dw_mipi_dsi_rockchip_config(dsi->slave);
+
+		clk_disable_unprepare(dsi->grf_clk);
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops dw_mipi_dsi_rockchip_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, dw_mipi_dsi_rockchip_resume)
+};
+
 static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1594,6 +1630,7 @@ struct platform_driver dw_mipi_dsi_rockchip_driver = {
 	.remove		= dw_mipi_dsi_rockchip_remove,
 	.driver		= {
 		.of_match_table = dw_mipi_dsi_rockchip_dt_ids,
+		.pm	= &dw_mipi_dsi_rockchip_pm_ops,
 		.name	= "dw-mipi-dsi-rockchip",
 	},
 };
-- 
2.33.0.685.g46640cef36-goog

Re: [PATCH v3 2/4] drm/rockchip: dsi: Reconfigure hardware on resume()

[Chen-Yu Tsai]

On Wed, Sep 29, 2021 at 5:36 AM Brian Norris <briannorris@chromium.org> wrote:
>
> Since commit 43c2de1002d2, we perform most HW configuration in the
> bind() function. This configuration may be lost on suspend/resume, so we
> need to call it again. That may lead to errors like this after system
> suspend/resume:
>
>   dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
>   panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110
>
> Tested on Acer Chromebook Tab 10 (RK3399 Gru-Scarlet).
>
> Note that early mailing list versions of this driver borrowed Rockchip's
> downstream/BSP solution, to do HW configuration in mode_set() (which
> *is* called at the appropriate pre-enable() times), but that was
> discarded along the way. I've avoided that still, because mode_set()
> documentation doesn't suggest this kind of purpose as far as I can tell.
>
> Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

Re: [PATCH v3 2/4] drm/rockchip: dsi: Reconfigure hardware on resume()

[Nícolas F. R. A. Prado]

On Tue, Sep 28, 2021 at 02:35:50PM -0700, Brian Norris wrote:
> Since commit 43c2de1002d2, we perform most HW configuration in the
> bind() function. This configuration may be lost on suspend/resume, so we
> need to call it again. That may lead to errors like this after system
> suspend/resume:
> 
>   dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
>   panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110
> 
> Tested on Acer Chromebook Tab 10 (RK3399 Gru-Scarlet).
> 
> Note that early mailing list versions of this driver borrowed Rockchip's
> downstream/BSP solution, to do HW configuration in mode_set() (which
> *is* called at the appropriate pre-enable() times), but that was
> discarded along the way. I've avoided that still, because mode_set()
> documentation doesn't suggest this kind of purpose as far as I can tell.
> 
> Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>

Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

Re: [PATCH v3 2/4] drm/rockchip: dsi: Reconfigure hardware on resume()

[Heiko Stuebner]

Am Dienstag, 28. September 2021, 23:35:50 CEST schrieb Brian Norris:
> Since commit 43c2de1002d2, we perform most HW configuration in the
> bind() function. This configuration may be lost on suspend/resume, so we
> need to call it again. That may lead to errors like this after system
> suspend/resume:
> 
>   dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO
>   panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110
> 
> Tested on Acer Chromebook Tab 10 (RK3399 Gru-Scarlet).
> 
> Note that early mailing list versions of this driver borrowed Rockchip's
> downstream/BSP solution, to do HW configuration in mode_set() (which
> *is* called at the appropriate pre-enable() times),

not always though. In non-atomic settings .mode_set actually doesn't
seem to be called every time. I've experienced this when drm disables
atomic when X11 is running.

So having real suspend/resume callbacks makes quite a lot of sense :-)


Heiko

> but that was
> discarded along the way. I've avoided that still, because mode_set()
> documentation doesn't suggest this kind of purpose as far as I can tell.
> 
> Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux to bind()")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
> 
> Changes in v3:
>  - New patch, to fix related PM issue discovered after patch 1
> 
>  .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c   | 37 +++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> index 45676b23c019..21c67343cc6c 100644
> --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> @@ -268,6 +268,8 @@ struct dw_mipi_dsi_rockchip {
>  	struct dw_mipi_dsi *dmd;
>  	const struct rockchip_dw_dsi_chip_data *cdata;
>  	struct dw_mipi_dsi_plat_data pdata;
> +
> +	bool dsi_bound;
>  };
>  
>  struct dphy_pll_parameter_map {
> @@ -964,6 +966,8 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev,
>  		goto out_pm_runtime;
>  	}
>  
> +	dsi->dsi_bound = true;
> +
>  	return 0;
>  
>  out_pm_runtime:
> @@ -983,6 +987,8 @@ static void dw_mipi_dsi_rockchip_unbind(struct device *dev,
>  	if (dsi->is_slave)
>  		return;
>  
> +	dsi->dsi_bound = false;
> +
>  	dw_mipi_dsi_unbind(dsi->dmd);
>  
>  	clk_disable_unprepare(dsi->pllref_clk);
> @@ -1277,6 +1283,36 @@ static const struct phy_ops dw_mipi_dsi_dphy_ops = {
>  	.exit		= dw_mipi_dsi_dphy_exit,
>  };
>  
> +static int __maybe_unused dw_mipi_dsi_rockchip_resume(struct device *dev)
> +{
> +	struct dw_mipi_dsi_rockchip *dsi = dev_get_drvdata(dev);
> +	int ret;
> +
> +	/*
> +	 * Re-configure DSI state, if we were previously initialized. We need
> +	 * to do this before rockchip_drm_drv tries to re-enable() any panels.
> +	 */
> +	if (dsi->dsi_bound) {
> +		ret = clk_prepare_enable(dsi->grf_clk);
> +		if (ret) {
> +			DRM_DEV_ERROR(dsi->dev, "Failed to enable grf_clk: %d\n", ret);
> +			return ret;
> +		}
> +
> +		dw_mipi_dsi_rockchip_config(dsi);
> +		if (dsi->slave)
> +			dw_mipi_dsi_rockchip_config(dsi->slave);
> +
> +		clk_disable_unprepare(dsi->grf_clk);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops dw_mipi_dsi_rockchip_pm_ops = {
> +	SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, dw_mipi_dsi_rockchip_resume)
> +};
> +
>  static int dw_mipi_dsi_rockchip_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -1594,6 +1630,7 @@ struct platform_driver dw_mipi_dsi_rockchip_driver = {
>  	.remove		= dw_mipi_dsi_rockchip_remove,
>  	.driver		= {
>  		.of_match_table = dw_mipi_dsi_rockchip_dt_ids,
> +		.pm	= &dw_mipi_dsi_rockchip_pm_ops,
>  		.name	= "dw-mipi-dsi-rockchip",
>  	},
>  };
>