linux-kernel - Re: [PATCH v2 2/6] drm/msm/dsi: set video mode widebus enable bit when widebus is enabled

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Message-ID: <6a05436d-a89f-43f9-b2d3-a664a6a36185@quicinc.com>
Date:   Thu, 7 Dec 2023 12:33:20 -0800
From:   Jessica Zhang <quic_jesszhan@...cinc.com>
To:     Jonathan Marek <jonathan@...ek.ca>,
        <freedreno@...ts.freedesktop.org>
CC:     Rob Clark <robdclark@...il.com>,
        Abhinav Kumar <quic_abhinavk@...cinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Sean Paul <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        "Konrad Dybcio" <konrad.dybcio@...aro.org>,
        Jiasheng Jiang <jiasheng@...as.ac.cn>,
        "open list:DRM DRIVER FOR MSM ADRENO GPU" 
        <linux-arm-msm@...r.kernel.org>,
        "open list:DRM DRIVER FOR MSM ADRENO GPU" 
        <dri-devel@...ts.freedesktop.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/6] drm/msm/dsi: set video mode widebus enable bit
 when widebus is enabled



On 11/14/2023 2:58 PM, Jonathan Marek wrote:
> The value returned by msm_dsi_wide_bus_enabled() doesn't match what the
> driver is doing in video mode. Fix that by actually enabling widebus for
> video mode.
> 
> Fixes: efcbd6f9cdeb ("drm/msm/dsi: Enable widebus for DSI")
> Signed-off-by: Jonathan Marek <jonathan@...ek.ca>
> ---
>   drivers/gpu/drm/msm/dsi/dsi.xml.h  | 1 +
>   drivers/gpu/drm/msm/dsi/dsi_host.c | 2 ++
>   2 files changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi.xml.h b/drivers/gpu/drm/msm/dsi/dsi.xml.h
> index 2a7d980e12c3..f0b3cdc020a1 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.xml.h
> +++ b/drivers/gpu/drm/msm/dsi/dsi.xml.h
> @@ -231,6 +231,7 @@ static inline uint32_t DSI_VID_CFG0_TRAFFIC_MODE(enum dsi_traffic_mode val)
>   #define DSI_VID_CFG0_HSA_POWER_STOP				0x00010000
>   #define DSI_VID_CFG0_HBP_POWER_STOP				0x00100000
>   #define DSI_VID_CFG0_HFP_POWER_STOP				0x01000000
> +#define DSI_VID_CFG0_DATABUS_WIDEN				0x02000000
>   #define DSI_VID_CFG0_PULSE_MODE_HSA_HE				0x10000000
>   
>   #define REG_DSI_VID_CFG1					0x0000001c
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index deeecdfd6c4e..f2c1cbd08d4d 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -745,6 +745,8 @@ static void dsi_ctrl_enable(struct msm_dsi_host *msm_host,
>   		data |= DSI_VID_CFG0_TRAFFIC_MODE(dsi_get_traffic_mode(flags));
>   		data |= DSI_VID_CFG0_DST_FORMAT(dsi_get_vid_fmt(mipi_fmt));
>   		data |= DSI_VID_CFG0_VIRT_CHANNEL(msm_host->channel);
> +		if (msm_dsi_host_is_wide_bus_enabled(&msm_host->base))
> +			data |= DSI_VID_CFG0_DATABUS_WIDEN;

Hi Jonathan,

Now that widebus is enabled for video mode, I think you can also drop 
the TODO here [1]. Other than that, this LGTM.

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

Thanks,

Jessica Zhang

[1] 
https://elixir.bootlin.com/linux/v6.7-rc3/source/drivers/gpu/drm/msm/dsi/dsi_host.c#L772

>   		dsi_write(msm_host, REG_DSI_VID_CFG0, data);
>   
>   		/* Do not swap RGB colors */
> -- 
> 2.26.1
>