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Date:   Thu, 10 Dec 2020 18:25:25 -0600
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Robert Foss <robert.foss@linaro.org>
Cc:     a.hajda@samsung.com, narmstrong@baylibre.com,
        Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se,
        jernej.skrabec@siol.net, airlied@linux.ie, daniel@ffwll.ch,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        John Stultz <john.stultz@linaro.org>,
        Peter Collingbourne <pcc@google.com>,
        Alistair Delva <adelva@google.com>,
        Vinod Koul <vinod.koul@linaro.org>,
        Anibal Limon <anibal.limon@linaro.org>
Subject: Re: [PATCH v1] drm/bridge: lt9611: Fix handling of 4k panels
Message-ID: <X9K8daO5DrKC+Ama@builder.lan>
References: <20201123104616.1412688-1-robert.foss@linaro.org>
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In-Reply-To: <20201123104616.1412688-1-robert.foss@linaro.org>
Precedence: bulk

On Mon 23 Nov 04:46 CST 2020, Robert Foss wrote:

> 4k requires two dsi pipes, so don't report MODE_OK when only a
> single pipe is configured. But rather report MODE_PANEL to
> signal that requirements of the panel are not being met.
> 
> Reported-by: Peter Collingbourne <pcc@google.com>
> Suggested-by: Peter Collingbourne <pcc@google.com>
> Signed-off-by: Robert Foss <robert.foss@linaro.org>
> Tested-by: John Stultz <john.stultz@linaro.org>

This looks very similar to what I had in the early revisions of the
driver.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Regards,
Bjorn

> ---
>  drivers/gpu/drm/bridge/lontium-lt9611.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
> index d734d9402c35..e8eb8deb444b 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9611.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
> @@ -867,8 +867,14 @@ static enum drm_mode_status lt9611_bridge_mode_valid(struct drm_bridge *bridge,
>  						     const struct drm_display_mode *mode)
>  {
>  	struct lt9611_mode *lt9611_mode = lt9611_find_mode(mode);
> +	struct lt9611 *lt9611 = bridge_to_lt9611(bridge);
>  
> -	return lt9611_mode ? MODE_OK : MODE_BAD;
> +	if (!lt9611_mode)
> +		return MODE_BAD;
> +	else if (lt9611_mode->intfs > 1 && !lt9611->dsi1)
> +		return MODE_PANEL;
> +	else
> +		return MODE_OK;
>  }
>  
>  static void lt9611_bridge_pre_enable(struct drm_bridge *bridge)
> -- 
> 2.27.0
>