[PATCH v7,0/4] Cooperate with DSI RX devices to modify dsi funcs and delay mipi high to cooperate with panel sequence

[PATCH v7,0/4] Cooperate with DSI RX devices to modify dsi funcs and delay mipi high to cooperate with panel sequence

[xinlei.lee]

From: Xinlei Lee <xinlei.lee@mediatek.com>

In upstream-v5.8, dsi_enable will operate panel_enable, but this
modification has been moved in v5.9. In order to ensure the timing of
dsi_power_on/off and the timing of pulling up/down the MIPI signal,
the modification of v5.9 is synchronized in this series of patches.

Change since v6:
1. Change comment back linux version to kernel 5.10.

Change since v5:
1. Merged [v5,1/5] drm/mediatek: Adjust the timing of mipi signal from
LP00 to LP11 to [v5,4/5] drm/mediatek: keep dsi as LP00 before dcs cmds
transfer, because in (v5,1/5) to adjust the dsi func sequence in order
to move to lane_ready func together in (v5, 4/5).

Changes since v4:
1. Dsi func modified to atomic operation.
2. Added fix tag.
3. Removed lane_ready print statement.

Changes since v3:
1. Rebase kernel-5.18-rc1.
2. Added dsi_enable protection.
3. Encapsulates the dsi_lane_ready function.

Changes since v2:
1. Rebase linux-next.

Changes since v1:
1. Dsi sequence marked with patch adjustment.
2. Fixes: mtk_dsi: Use the drm_panel_bridge.

Jitao Shi (2):
  drm/mediatek: Separate poweron/poweroff from enable/disable and define
    new funcs
  drm/mediatek: keep dsi as LP00 before dcs cmds transfer

Xinlei Lee (2):
  drm/mediatek: Modify dsi funcs to atomic operations
  drm/mediatek: Add pull-down MIPI operation in mtk_dsi_poweroff
    function

 drivers/gpu/drm/mediatek/mtk_dsi.c | 93 ++++++++++++++++++++----------
 1 file changed, 63 insertions(+), 30 deletions(-)

-- 
2.18.0

[PATCH v7,1/4] drm/mediatek: Modify dsi funcs to atomic operations

[xinlei.lee]

From: Xinlei Lee <xinlei.lee@mediatek.com>

Because .enable & .disable are deprecated.
Use .atomic_enable & .atomic_disable instead.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index bd3f5b485085..f880136cec09 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -763,14 +763,16 @@ static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
 	drm_display_mode_to_videomode(adjusted, &dsi->vm);
 }
 
-static void mtk_dsi_bridge_disable(struct drm_bridge *bridge)
+static void mtk_dsi_bridge_atomic_disable(struct drm_bridge *bridge,
+					  struct drm_bridge_state *old_bridge_state)
 {
 	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
 	mtk_output_dsi_disable(dsi);
 }
 
-static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
+static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
+					 struct drm_bridge_state *old_bridge_state)
 {
 	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
@@ -779,8 +781,8 @@ static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
 
 static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
 	.attach = mtk_dsi_bridge_attach,
-	.disable = mtk_dsi_bridge_disable,
-	.enable = mtk_dsi_bridge_enable,
+	.atomic_disable = mtk_dsi_bridge_atomic_disable,
+	.atomic_enable = mtk_dsi_bridge_atomic_enable,
 	.mode_set = mtk_dsi_bridge_mode_set,
 };
 
-- 
2.18.0

[PATCH v7,2/4] drm/mediatek: Separate poweron/poweroff from enable/disable and define new funcs

[xinlei.lee]

From: Jitao Shi <jitao.shi@mediatek.com>

In order to match the changes of "Use the drm_panel_bridge API",
the poweron/poweroff of dsi is extracted from enable/disable and
defined as new funcs (atomic_pre_enable/atomic_post_disable).

Since dsi_poweron is moved from dsi_enable to pre_enable function, in
order to avoid poweron failure, the operation of dsi register fails to
cause bus hang. Therefore, the protection mechanism is added to the
dsi_enable function.

Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge API")

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 53 +++++++++++++++++++-----------
 1 file changed, 34 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index f880136cec09..d9a6b928dba8 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -691,16 +691,6 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 	if (--dsi->refcount != 0)
 		return;
 
-	/*
-	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
-	 * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
-	 * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
-	 * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
-	 * after dsi is fully set.
-	 */
-	mtk_dsi_stop(dsi);
-
-	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
 	mtk_dsi_reset_engine(dsi);
 	mtk_dsi_lane0_ulp_mode_enter(dsi);
 	mtk_dsi_clk_ulp_mode_enter(dsi);
@@ -715,17 +705,9 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 
 static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
 {
-	int ret;
-
 	if (dsi->enabled)
 		return;
 
-	ret = mtk_dsi_poweron(dsi);
-	if (ret < 0) {
-		DRM_ERROR("failed to power on dsi\n");
-		return;
-	}
-
 	mtk_dsi_set_mode(dsi);
 	mtk_dsi_clk_hs_mode(dsi, 1);
 
@@ -739,7 +721,16 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
 	if (!dsi->enabled)
 		return;
 
-	mtk_dsi_poweroff(dsi);
+	/*
+	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
+	 * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
+	 * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
+	 * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
+	 * after dsi is fully set.
+	 */
+	mtk_dsi_stop(dsi);
+
+	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
 
 	dsi->enabled = false;
 }
@@ -776,13 +767,37 @@ static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
 {
 	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
+	if (dsi->refcount == 0)
+		return;
+
 	mtk_output_dsi_enable(dsi);
 }
 
+static void mtk_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
+					     struct drm_bridge_state *old_bridge_state)
+{
+	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
+	int ret;
+
+	ret = mtk_dsi_poweron(dsi);
+	if (ret < 0)
+		DRM_ERROR("failed to power on dsi\n");
+}
+
+static void mtk_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,
+					       struct drm_bridge_state *old_bridge_state)
+{
+	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
+
+	mtk_dsi_poweroff(dsi);
+}
+
 static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
 	.attach = mtk_dsi_bridge_attach,
 	.atomic_disable = mtk_dsi_bridge_atomic_disable,
 	.atomic_enable = mtk_dsi_bridge_atomic_enable,
+	.atomic_pre_enable = mtk_dsi_bridge_atomic_pre_enable,
+	.atomic_post_disable = mtk_dsi_bridge_atomic_post_disable,
 	.mode_set = mtk_dsi_bridge_mode_set,
 };
 
-- 
2.18.0

[PATCH v7,3/4] drm/mediatek: keep dsi as LP00 before dcs cmds transfer

[xinlei.lee]

From: Jitao Shi <jitao.shi@mediatek.com>

To comply with the panel sequence, hold the mipi signal to LP00 before the dcs cmds transmission,
and pull the mipi signal high from LP00 to LP11 until the start of the dcs cmds transmission.
The normal panel timing is :
(1) pp1800 DC pull up
(2) avdd & avee AC pull high
(3) lcm_reset pull high -> pull low -> pull high
(4) Pull MIPI signal high (LP11) -> initial code -> send video data(HS mode)
The power-off sequence is reversed.
If dsi is not in cmd mode, then dsi will pull the mipi signal high in the mtk_output_dsi_enable function.
The delay in lane_ready func is the reaction time of dsi_rx after pulling up the mipi signal.

Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge API")

Cc: <stable@vger.kernel.org> # 5.10.x: b255d51e3967: sched: Modify dsi funcs to atomic operations
Cc: <stable@vger.kernel.org> # 5.10.x: 72c69c977502: sched: Separate poweron/poweroff from enable/disable and define new funcs
Cc: <stable@vger.kernel.org> # 5.10.x
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index d9a6b928dba8..25e84d9426bf 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -203,6 +203,7 @@ struct mtk_dsi {
 	struct mtk_phy_timing phy_timing;
 	int refcount;
 	bool enabled;
+	bool lanes_ready;
 	u32 irq_data;
 	wait_queue_head_t irq_wait_queue;
 	const struct mtk_dsi_driver_data *driver_data;
@@ -661,18 +662,11 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
 	mtk_dsi_reset_engine(dsi);
 	mtk_dsi_phy_timconfig(dsi);
 
-	mtk_dsi_rxtx_control(dsi);
-	usleep_range(30, 100);
-	mtk_dsi_reset_dphy(dsi);
 	mtk_dsi_ps_control_vact(dsi);
 	mtk_dsi_set_vm_cmd(dsi);
 	mtk_dsi_config_vdo_timing(dsi);
 	mtk_dsi_set_interrupt_enable(dsi);
 
-	mtk_dsi_clk_ulp_mode_leave(dsi);
-	mtk_dsi_lane0_ulp_mode_leave(dsi);
-	mtk_dsi_clk_hs_mode(dsi, 0);
-
 	return 0;
 err_disable_engine_clk:
 	clk_disable_unprepare(dsi->engine_clk);
@@ -701,6 +695,23 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 	clk_disable_unprepare(dsi->digital_clk);
 
 	phy_power_off(dsi->phy);
+
+	dsi->lanes_ready = false;
+}
+
+static void mtk_dsi_lane_ready(struct mtk_dsi *dsi)
+{
+	if (!dsi->lanes_ready) {
+		dsi->lanes_ready = true;
+		mtk_dsi_rxtx_control(dsi);
+		usleep_range(30, 100);
+		mtk_dsi_reset_dphy(dsi);
+		mtk_dsi_clk_ulp_mode_leave(dsi);
+		mtk_dsi_lane0_ulp_mode_leave(dsi);
+		mtk_dsi_clk_hs_mode(dsi, 0);
+		msleep(20);
+		/* The reaction time after pulling up the mipi signal for dsi_rx */
+	}
 }
 
 static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
@@ -708,6 +719,7 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
 	if (dsi->enabled)
 		return;
 
+	mtk_dsi_lane_ready(dsi);
 	mtk_dsi_set_mode(dsi);
 	mtk_dsi_clk_hs_mode(dsi, 1);
 
@@ -1017,6 +1029,8 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
 	if (MTK_DSI_HOST_IS_READ(msg->type))
 		irq_flag |= LPRX_RD_RDY_INT_FLAG;
 
+	mtk_dsi_lane_ready(dsi);
+
 	ret = mtk_dsi_host_send_cmd(dsi, msg, irq_flag);
 	if (ret)
 		goto restore_dsi_mode;
-- 
2.18.0

[PATCH v7,4/4] drm/mediatek: Add pull-down MIPI operation in mtk_dsi_poweroff function

[xinlei.lee]

From: Xinlei Lee <xinlei.lee@mediatek.com>

In the dsi_enable function, mtk_dsi_rxtx_control is to
pull up the MIPI signal operation. Before dsi_disable,
MIPI should also be pulled down by writing a register
instead of disabling dsi.

If disable dsi without pulling the mipi signal low, the value of
the register will still maintain the setting of the mipi signal being
pulled high.
After resume, even if the mipi signal is not pulled high, it will still
be in the high state.

Fixes: 2e54c14e310f ("drm/mediatek: Add DSI sub driver")

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 25e84d9426bf..79c906868bc2 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -688,6 +688,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 	mtk_dsi_reset_engine(dsi);
 	mtk_dsi_lane0_ulp_mode_enter(dsi);
 	mtk_dsi_clk_ulp_mode_enter(dsi);
+	/* set the lane number as 0 to pull down mipi */
+	writel(0, dsi->regs + DSI_TXRX_CTRL);
 
 	mtk_dsi_disable(dsi);
 
-- 
2.18.0

Re: [PATCH v7,1/4] drm/mediatek: Modify dsi funcs to atomic operations

[Rex-BC Chen]

On Fri, 2022-05-20 at 10:00 +0800, xinlei.lee@mediatek.com wrote:
> From: Xinlei Lee <xinlei.lee@mediatek.com>
> 
> Because .enable & .disable are deprecated.
> Use .atomic_enable & .atomic_disable instead.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> Reviewed-by: CK Hu <ck.hu@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index bd3f5b485085..f880136cec09 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -763,14 +763,16 @@ static void mtk_dsi_bridge_mode_set(struct
> drm_bridge *bridge,
>  	drm_display_mode_to_videomode(adjusted, &dsi->vm);
>  }
>  
> -static void mtk_dsi_bridge_disable(struct drm_bridge *bridge)
> +static void mtk_dsi_bridge_atomic_disable(struct drm_bridge *bridge,
> +					  struct drm_bridge_state
> *old_bridge_state)
>  {
>  	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>  
>  	mtk_output_dsi_disable(dsi);
>  }
>  
> -static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
> +static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
> +					 struct drm_bridge_state
> *old_bridge_state)
>  {
>  	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>  
> @@ -779,8 +781,8 @@ static void mtk_dsi_bridge_enable(struct
> drm_bridge *bridge)
>  
>  static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
>  	.attach = mtk_dsi_bridge_attach,
> -	.disable = mtk_dsi_bridge_disable,
> -	.enable = mtk_dsi_bridge_enable,
> +	.atomic_disable = mtk_dsi_bridge_atomic_disable,
> +	.atomic_enable = mtk_dsi_bridge_atomic_enable,
>  	.mode_set = mtk_dsi_bridge_mode_set,
>  };
>  

Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>

Re: [PATCH v7,3/4] drm/mediatek: keep dsi as LP00 before dcs cmds transfer

[Rex-BC Chen]

On Fri, 2022-05-20 at 10:00 +0800, xinlei.lee@mediatek.com wrote:
> From: Jitao Shi <jitao.shi@mediatek.com>
> 
> To comply with the panel sequence, hold the mipi signal to LP00
> before the dcs cmds transmission,
> and pull the mipi signal high from LP00 to LP11 until the start of
> the dcs cmds transmission.
> The normal panel timing is :
> (1) pp1800 DC pull up
> (2) avdd & avee AC pull high
> (3) lcm_reset pull high -> pull low -> pull high
> (4) Pull MIPI signal high (LP11) -> initial code -> send video
> data(HS mode)
> The power-off sequence is reversed.
> If dsi is not in cmd mode, then dsi will pull the mipi signal high in
> the mtk_output_dsi_enable function.
> The delay in lane_ready func is the reaction time of dsi_rx after
> pulling up the mipi signal.
> 
> Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge
> API")
> 
> Cc: <stable@vger.kernel.org> # 5.10.x: b255d51e3967: sched: Modify
> dsi funcs to atomic operations
> Cc: <stable@vger.kernel.org> # 5.10.x: 72c69c977502: sched: Separate
> poweron/poweroff from enable/disable and define new funcs
> Cc: <stable@vger.kernel.org> # 5.10.x
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> ---

Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>

Re: [PATCH v7, 2/4] drm/mediatek: Separate poweron/poweroff from enable/disable and define new funcs

[CK Hu]

Hi, Xinlei:

On Fri, 2022-05-20 at 10:00 +0800, xinlei.lee@mediatek.com wrote:
> From: Jitao Shi <jitao.shi@mediatek.com>
> 
> In order to match the changes of "Use the drm_panel_bridge API",
> the poweron/poweroff of dsi is extracted from enable/disable and
> defined as new funcs (atomic_pre_enable/atomic_post_disable).
> 
> Since dsi_poweron is moved from dsi_enable to pre_enable function, in
> order to avoid poweron failure, the operation of dsi register fails
> to
> cause bus hang. Therefore, the protection mechanism is added to the
> dsi_enable function.

Reviewed-by: CK Hu <ck.hu@mediatek.com>

> 
> Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge
> API")
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 53 +++++++++++++++++++---------
> --
>  1 file changed, 34 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index f880136cec09..d9a6b928dba8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -691,16 +691,6 @@ static void mtk_dsi_poweroff(struct mtk_dsi
> *dsi)
>  	if (--dsi->refcount != 0)
>  		return;
>  
> -	/*
> -	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
> -	 * mtk_dsi_stop() should be called after
> mtk_drm_crtc_atomic_disable(),
> -	 * which needs irq for vblank, and mtk_dsi_stop() will disable
> irq.
> -	 * mtk_dsi_start() needs to be called in
> mtk_output_dsi_enable(),
> -	 * after dsi is fully set.
> -	 */
> -	mtk_dsi_stop(dsi);
> -
> -	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
>  	mtk_dsi_reset_engine(dsi);
>  	mtk_dsi_lane0_ulp_mode_enter(dsi);
>  	mtk_dsi_clk_ulp_mode_enter(dsi);
> @@ -715,17 +705,9 @@ static void mtk_dsi_poweroff(struct mtk_dsi
> *dsi)
>  
>  static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
>  {
> -	int ret;
> -
>  	if (dsi->enabled)
>  		return;
>  
> -	ret = mtk_dsi_poweron(dsi);
> -	if (ret < 0) {
> -		DRM_ERROR("failed to power on dsi\n");
> -		return;
> -	}
> -
>  	mtk_dsi_set_mode(dsi);
>  	mtk_dsi_clk_hs_mode(dsi, 1);
>  
> @@ -739,7 +721,16 @@ static void mtk_output_dsi_disable(struct
> mtk_dsi *dsi)
>  	if (!dsi->enabled)
>  		return;
>  
> -	mtk_dsi_poweroff(dsi);
> +	/*
> +	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
> +	 * mtk_dsi_stop() should be called after
> mtk_drm_crtc_atomic_disable(),
> +	 * which needs irq for vblank, and mtk_dsi_stop() will disable
> irq.
> +	 * mtk_dsi_start() needs to be called in
> mtk_output_dsi_enable(),
> +	 * after dsi is fully set.
> +	 */
> +	mtk_dsi_stop(dsi);
> +
> +	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
>  
>  	dsi->enabled = false;
>  }
> @@ -776,13 +767,37 @@ static void mtk_dsi_bridge_atomic_enable(struct
> drm_bridge *bridge,
>  {
>  	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>  
> +	if (dsi->refcount == 0)
> +		return;
> +
>  	mtk_output_dsi_enable(dsi);
>  }
>  
> +static void mtk_dsi_bridge_atomic_pre_enable(struct drm_bridge
> *bridge,
> +					     struct drm_bridge_state
> *old_bridge_state)
> +{
> +	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> +	int ret;
> +
> +	ret = mtk_dsi_poweron(dsi);
> +	if (ret < 0)
> +		DRM_ERROR("failed to power on dsi\n");
> +}
> +
> +static void mtk_dsi_bridge_atomic_post_disable(struct drm_bridge
> *bridge,
> +					       struct drm_bridge_state
> *old_bridge_state)
> +{
> +	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> +
> +	mtk_dsi_poweroff(dsi);
> +}
> +
>  static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
>  	.attach = mtk_dsi_bridge_attach,
>  	.atomic_disable = mtk_dsi_bridge_atomic_disable,
>  	.atomic_enable = mtk_dsi_bridge_atomic_enable,
> +	.atomic_pre_enable = mtk_dsi_bridge_atomic_pre_enable,
> +	.atomic_post_disable = mtk_dsi_bridge_atomic_post_disable,
>  	.mode_set = mtk_dsi_bridge_mode_set,
>  };
>  

Re: [PATCH v7, 3/4] drm/mediatek: keep dsi as LP00 before dcs cmds transfer

[CK Hu]

Hi, Xinlei:

On Fri, 2022-05-20 at 10:00 +0800, xinlei.lee@mediatek.com wrote:
> From: Jitao Shi <jitao.shi@mediatek.com>
> 
> To comply with the panel sequence, hold the mipi signal to LP00
> before the dcs cmds transmission,
> and pull the mipi signal high from LP00 to LP11 until the start of
> the dcs cmds transmission.
> The normal panel timing is :
> (1) pp1800 DC pull up
> (2) avdd & avee AC pull high
> (3) lcm_reset pull high -> pull low -> pull high
> (4) Pull MIPI signal high (LP11) -> initial code -> send video
> data(HS mode)
> The power-off sequence is reversed.
> If dsi is not in cmd mode, then dsi will pull the mipi signal high in
> the mtk_output_dsi_enable function.
> The delay in lane_ready func is the reaction time of dsi_rx after
> pulling up the mipi signal.

Reviewed-by: CK Hu <ck.hu@mediatek.com>

> 
> Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge
> API")
> 
> Cc: <stable@vger.kernel.org> # 5.10.x: b255d51e3967: sched: Modify
> dsi funcs to atomic operations
> Cc: <stable@vger.kernel.org> # 5.10.x: 72c69c977502: sched: Separate
> poweron/poweroff from enable/disable and define new funcs
> Cc: <stable@vger.kernel.org> # 5.10.x
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 28 +++++++++++++++++++++-------
>  1 file changed, 21 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index d9a6b928dba8..25e84d9426bf 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -203,6 +203,7 @@ struct mtk_dsi {
>  	struct mtk_phy_timing phy_timing;
>  	int refcount;
>  	bool enabled;
> +	bool lanes_ready;
>  	u32 irq_data;
>  	wait_queue_head_t irq_wait_queue;
>  	const struct mtk_dsi_driver_data *driver_data;
> @@ -661,18 +662,11 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
>  	mtk_dsi_reset_engine(dsi);
>  	mtk_dsi_phy_timconfig(dsi);
>  
> -	mtk_dsi_rxtx_control(dsi);
> -	usleep_range(30, 100);
> -	mtk_dsi_reset_dphy(dsi);
>  	mtk_dsi_ps_control_vact(dsi);
>  	mtk_dsi_set_vm_cmd(dsi);
>  	mtk_dsi_config_vdo_timing(dsi);
>  	mtk_dsi_set_interrupt_enable(dsi);
>  
> -	mtk_dsi_clk_ulp_mode_leave(dsi);
> -	mtk_dsi_lane0_ulp_mode_leave(dsi);
> -	mtk_dsi_clk_hs_mode(dsi, 0);
> -
>  	return 0;
>  err_disable_engine_clk:
>  	clk_disable_unprepare(dsi->engine_clk);
> @@ -701,6 +695,23 @@ static void mtk_dsi_poweroff(struct mtk_dsi
> *dsi)
>  	clk_disable_unprepare(dsi->digital_clk);
>  
>  	phy_power_off(dsi->phy);
> +
> +	dsi->lanes_ready = false;
> +}
> +
> +static void mtk_dsi_lane_ready(struct mtk_dsi *dsi)
> +{
> +	if (!dsi->lanes_ready) {
> +		dsi->lanes_ready = true;
> +		mtk_dsi_rxtx_control(dsi);
> +		usleep_range(30, 100);
> +		mtk_dsi_reset_dphy(dsi);
> +		mtk_dsi_clk_ulp_mode_leave(dsi);
> +		mtk_dsi_lane0_ulp_mode_leave(dsi);
> +		mtk_dsi_clk_hs_mode(dsi, 0);
> +		msleep(20);
> +		/* The reaction time after pulling up the mipi signal
> for dsi_rx */
> +	}
>  }
>  
>  static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
> @@ -708,6 +719,7 @@ static void mtk_output_dsi_enable(struct mtk_dsi
> *dsi)
>  	if (dsi->enabled)
>  		return;
>  
> +	mtk_dsi_lane_ready(dsi);
>  	mtk_dsi_set_mode(dsi);
>  	mtk_dsi_clk_hs_mode(dsi, 1);
>  
> @@ -1017,6 +1029,8 @@ static ssize_t mtk_dsi_host_transfer(struct
> mipi_dsi_host *host,
>  	if (MTK_DSI_HOST_IS_READ(msg->type))
>  		irq_flag |= LPRX_RD_RDY_INT_FLAG;
>  
> +	mtk_dsi_lane_ready(dsi);
> +
>  	ret = mtk_dsi_host_send_cmd(dsi, msg, irq_flag);
>  	if (ret)
>  		goto restore_dsi_mode;

Re: [PATCH v7, 2/4] drm/mediatek: Separate poweron/poweroff from enable/disable and define new funcs

[AngeloGioacchino Del Regno]

Il 20/05/22 04:00, xinlei.lee@mediatek.com ha scritto:
> From: Jitao Shi <jitao.shi@mediatek.com>
> 
> In order to match the changes of "Use the drm_panel_bridge API",
> the poweron/poweroff of dsi is extracted from enable/disable and
> defined as new funcs (atomic_pre_enable/atomic_post_disable).
> 
> Since dsi_poweron is moved from dsi_enable to pre_enable function, in
> order to avoid poweron failure, the operation of dsi register fails to
> cause bus hang. Therefore, the protection mechanism is added to the
> dsi_enable function.
> 
> Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge API")
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> Reviewed-by: CK Hu <ck.hu@mediatek.com>

Hello Xinlei, CK, maintainers:

This patch is breaking machines that are using a DSI->DisplayPort bridge (like
the ANX7625 chip), but that's not the main issue.

----> I have never given a Reviewed-by tag for this commit <----

It's true I've given my tag for an older version [1] of this one, which was *not*
using atomic_* callbacks and that one worked fine (which is why I gave you
my R-b tag for it).

You have changed commits in this series to use atomic_(pre_)enable callbacks
but kept my tag, which is seriously wrong - and even more, because it's actually
breaking display support for a generous number of Chromebooks upstream.


Please be careful next time and ask for a new review when you make substantial
changes to your commits.


Anyway, I have already sent a fix for this situation, please look at [2].

Regards,
Angelo

[1]: 
https://patchwork.kernel.org/project/linux-mediatek/patch/1649644308-8455-3-git-send-email-xinlei.lee@mediatek.com/

[2]: 
https://lore.kernel.org/lkml/20220721172727.14624-1-angelogioacchino.delregno@collabora.com/T/#u

> ---
>   drivers/gpu/drm/mediatek/mtk_dsi.c | 53 +++++++++++++++++++-----------
>   1 file changed, 34 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index f880136cec09..d9a6b928dba8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -691,16 +691,6 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>   	if (--dsi->refcount != 0)
>   		return;
>   
> -	/*
> -	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
> -	 * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
> -	 * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
> -	 * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
> -	 * after dsi is fully set.
> -	 */
> -	mtk_dsi_stop(dsi);
> -
> -	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
>   	mtk_dsi_reset_engine(dsi);
>   	mtk_dsi_lane0_ulp_mode_enter(dsi);
>   	mtk_dsi_clk_ulp_mode_enter(dsi);
> @@ -715,17 +705,9 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>   
>   static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
>   {
> -	int ret;
> -
>   	if (dsi->enabled)
>   		return;
>   
> -	ret = mtk_dsi_poweron(dsi);
> -	if (ret < 0) {
> -		DRM_ERROR("failed to power on dsi\n");
> -		return;
> -	}
> -
>   	mtk_dsi_set_mode(dsi);
>   	mtk_dsi_clk_hs_mode(dsi, 1);
>   
> @@ -739,7 +721,16 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
>   	if (!dsi->enabled)
>   		return;
>   
> -	mtk_dsi_poweroff(dsi);
> +	/*
> +	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
> +	 * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
> +	 * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
> +	 * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
> +	 * after dsi is fully set.
> +	 */
> +	mtk_dsi_stop(dsi);
> +
> +	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
>   
>   	dsi->enabled = false;
>   }
> @@ -776,13 +767,37 @@ static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
>   {
>   	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>   
> +	if (dsi->refcount == 0)
> +		return;
> +
>   	mtk_output_dsi_enable(dsi);
>   }
>   
> +static void mtk_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
> +					     struct drm_bridge_state *old_bridge_state)
> +{
> +	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> +	int ret;
> +
> +	ret = mtk_dsi_poweron(dsi);
> +	if (ret < 0)
> +		DRM_ERROR("failed to power on dsi\n");
> +}
> +
> +static void mtk_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,
> +					       struct drm_bridge_state *old_bridge_state)
> +{
> +	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> +
> +	mtk_dsi_poweroff(dsi);
> +}
> +
>   static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
>   	.attach = mtk_dsi_bridge_attach,
>   	.atomic_disable = mtk_dsi_bridge_atomic_disable,
>   	.atomic_enable = mtk_dsi_bridge_atomic_enable,
> +	.atomic_pre_enable = mtk_dsi_bridge_atomic_pre_enable,
> +	.atomic_post_disable = mtk_dsi_bridge_atomic_post_disable,
>   	.mode_set = mtk_dsi_bridge_mode_set,
>   };
>