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Date:   Thu, 23 Jul 2020 16:11:51 +0530
From:   Vinod Koul <vkoul@kernel.org>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Sam Ravnborg <sam@ravnborg.org>
Cc:     Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
        Rob Clark <robdclark@gmail.com>, linux-arm-msm@vger.kernel.org,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Andrzej Hajda <a.hajda@samsung.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Emil Velikov <emil.l.velikov@gmail.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        John Stultz <john.stultz@linaro.org>
Subject: Re: [PATCH v5 3/4] drm/bridge: Introduce LT9611 DSI to HDMI bridge
Message-ID: <20200723104151.GY12965@vkoul-mobl>
References: <20200708103559.132300-1-vkoul@kernel.org>
 <20200708103559.132300-4-vkoul@kernel.org>
 <20200719171806.GA55541@ravnborg.org>
 <20200722131430.GJ5833@pendragon.ideasonboard.com>
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Hi Sam, Laurent,

On 22-07-20, 16:14, Laurent Pinchart wrote:
> > > +static int lt9611_bridge_attach(struct drm_bridge *bridge,
> > > +				enum drm_bridge_attach_flags flags)
> > > +{
> > > +	struct lt9611 *lt9611 = bridge_to_lt9611(bridge);
> > > +	int ret;
> > > +
> > > +	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
> > > +		dev_err(lt9611->dev, "Fix bridge driver to make connector optional!");
> > > +		return -EINVAL;
> > > +	}
> >
> > This should say that the display driver should be fixed.
> > If a display driver expects this bridge to create the connector
> > it would not work.
> 
> Actually, for new bridge drivers, connector creation should be optional
> from the start. We don't want a failure in that case, the feature should
> be implemented.

Yes this is causing issues for me now !. The patch 4/4 adds support in
msm/dsi but causes regression on qualcomm laptops with ti-sn65dsi86 eDP
bridge. I tried to fix that up with changes like Laurent has done for
adv7511, but it hasnt worked yet for me (remote debug of this is bit
painful)

So I am going to drop patch 4 from this series and add support for both
DRM_BRIDGE_ATTACH_NO_CONNECTOR set and cleared (like we have in adv7511)
so that it can work in both cases, while I fix all bridge uses of
msm/dsi and then we can drop these. Does that sound okay to you folks?

-- 
~Vinod