[PATCH] drm/panel: ltk050h3146w: Set burst mode for ltk050h3148w

[PATCH] drm/panel: ltk050h3146w: Set burst mode for ltk050h3148w

[Farouk Bouabid]

The ltk050h3148w variant expects the horizontal component lane byte clock
cycle(lbcc) to be calculated using lane_mbps (burst mode) instead of the
pixel clock.
Using the pixel clock rate by default for this calculation was introduced
in commit ac87d23694f4 ("drm/bridge: synopsys: dw-mipi-dsi: Use pixel clock
rate to calculate lbcc") and starting from commit 93e82bb4de01
("drm/bridge: synopsys: dw-mipi-dsi: Fix hcomponent lbcc for burst mode")
only panels that support burst mode can keep using the lane_mbps. So add
MIPI_DSI_MODE_VIDEO_BURST as part of the mode_flags for the dsi host.

Fixes: 93e82bb4de01 ("drm/bridge: synopsys: dw-mipi-dsi: Fix hcomponent lbcc for burst mode")
Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
---
 drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
index 6e3670508e3a..30919c872ac8 100644
--- a/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
+++ b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
@@ -326,7 +326,7 @@ static const struct drm_display_mode ltk050h3148w_mode = {
 static const struct ltk050h3146w_desc ltk050h3148w_data = {
 	.mode = &ltk050h3148w_mode,
 	.init = ltk050h3148w_init_sequence,
-	.mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE,
+	.mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE | MIPI_DSI_MODE_VIDEO_BURST,
 };
 
 static int ltk050h3146w_init_sequence(struct ltk050h3146w *ctx)
-- 
2.34.1

Re: [PATCH] drm/panel: ltk050h3146w: Set burst mode for ltk050h3148w

[Jessica Zhang]

On 12/13/2023 6:50 AM, Farouk Bouabid wrote:
> The ltk050h3148w variant expects the horizontal component lane byte clock
> cycle(lbcc) to be calculated using lane_mbps (burst mode) instead of the
> pixel clock.
> Using the pixel clock rate by default for this calculation was introduced
> in commit ac87d23694f4 ("drm/bridge: synopsys: dw-mipi-dsi: Use pixel clock
> rate to calculate lbcc") and starting from commit 93e82bb4de01
> ("drm/bridge: synopsys: dw-mipi-dsi: Fix hcomponent lbcc for burst mode")
> only panels that support burst mode can keep using the lane_mbps. So add
> MIPI_DSI_MODE_VIDEO_BURST as part of the mode_flags for the dsi host.
> 
> Fixes: 93e82bb4de01 ("drm/bridge: synopsys: dw-mipi-dsi: Fix hcomponent lbcc for burst mode")
> Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>

Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>

Thanks,

Jessica Zhang

> ---
>   drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
> index 6e3670508e3a..30919c872ac8 100644
> --- a/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
> +++ b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
> @@ -326,7 +326,7 @@ static const struct drm_display_mode ltk050h3148w_mode = {
>   static const struct ltk050h3146w_desc ltk050h3148w_data = {
>   	.mode = &ltk050h3148w_mode,
>   	.init = ltk050h3148w_init_sequence,
> -	.mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE,
> +	.mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE | MIPI_DSI_MODE_VIDEO_BURST,
>   };
>   
>   static int ltk050h3146w_init_sequence(struct ltk050h3146w *ctx)
> -- 
> 2.34.1
> 

Re: [PATCH] drm/panel: ltk050h3146w: Set burst mode for ltk050h3148w

[Heiko Stuebner]

On Wed, 13 Dec 2023 15:50:45 +0100, Farouk Bouabid wrote:
> The ltk050h3148w variant expects the horizontal component lane byte clock
> cycle(lbcc) to be calculated using lane_mbps (burst mode) instead of the
> pixel clock.
> Using the pixel clock rate by default for this calculation was introduced
> in commit ac87d23694f4 ("drm/bridge: synopsys: dw-mipi-dsi: Use pixel clock
> rate to calculate lbcc") and starting from commit 93e82bb4de01
> ("drm/bridge: synopsys: dw-mipi-dsi: Fix hcomponent lbcc for burst mode")
> only panels that support burst mode can keep using the lane_mbps. So add
> MIPI_DSI_MODE_VIDEO_BURST as part of the mode_flags for the dsi host.
> 
> [...]

Applied, thanks!

[1/1] drm/panel: ltk050h3146w: Set burst mode for ltk050h3148w
      commit: 6c9dbee84cd005bed5f9d07b3a2797ae6414b435

Best regards,
-- 
Heiko Stuebner <heiko@sntech.de>