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Message-ID: <7083b139-b6f7-44ed-b294-5c69fceed604@quicinc.com>
Date:   Wed, 13 Dec 2023 09:15:25 -0800
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Subject: Re: [PATCH] drm/panel: ltk050h3146w: Set burst mode for ltk050h3148w
Content-Language: en-US
To:     Farouk Bouabid <farouk.bouabid@theobroma-systems.com>,
        <quentin.schulz@theobroma-systems.com>,
        <neil.armstrong@linaro.org>, <sam@ravnborg.org>,
        <maarten.lankhorst@linux.intel.com>, <mripard@kernel.org>,
        <tzimmermann@suse.de>, <airlied@gmail.com>, <daniel@ffwll.ch>
CC:     <heiko@sntech.de>, <victor.liu@nxp.com>,
        <dri-devel@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>
References: <20231213145045.41020-1-farouk.bouabid@theobroma-systems.com>
From:   Jessica Zhang <quic_jesszhan@quicinc.com>
In-Reply-To: <20231213145045.41020-1-farouk.bouabid@theobroma-systems.com>
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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
>