2023-12-13 14:55:32

by Farouk Bouabid

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

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 <[email protected]>
---
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

2023-12-13 17:16:13

by Jessica Zhang

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

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 <[email protected]>

Reviewed-by: Jessica Zhang <[email protected]>

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
>

2023-12-13 17:44:44

by Heiko Stübner

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

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 <[email protected]>