linux-kernel - Re: [PATCH 7/7] drm/msm/dpu: remove DPU_CTL_SPLIT

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Message-ID: <6utf3iirzf7vtotsjxswtiuodt75mtrmhlofvsju5qfdmx7sdk@6mflw7g67ljy>
Date: Fri, 28 Feb 2025 06:03:55 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Marijn Suijten <marijn.suijten@...ainline.org>
Cc: Rob Clark <robdclark@...il.com>, 
	Abhinav Kumar <quic_abhinavk@...cinc.com>, Sean Paul <sean@...rly.run>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, linux-arm-msm@...r.kernel.org, dri-devel@...ts.freedesktop.org, 
	freedreno@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 7/7] drm/msm/dpu: remove DPU_CTL_SPLIT_DISPLAY from CTL
 blocks on DPU >= 5.0

On Fri, Feb 21, 2025 at 12:37:40AM +0100, Marijn Suijten wrote:
> On 2025-02-20 12:26:24, Dmitry Baryshkov wrote:
> > Since DPU 5.0 CTL blocks do not require DPU_CTL_SPLIT_DISPLAY, as single
> > CTL is used for both interfaces. As both RM and encoder now handle
> > active CTLs, drop that feature bit.
> 
> I was wondering if this bit only existed to ensure the right "pair" of CTLs
> exist: not on DPU 4.0, but on DPU 3.0 we see that CTL_0 and CTL_2 have this bit
> but not CTL_1.  Meaning that split display can only work when that specific pair
> of CTL_0 and CTL_2 is used in conjunction?

Unfortunately I don't have a deep knowledge of those platforms and I
don't have a way to test it. My SDM660 board (IFC6560) doesn't have DSI1
routed anywhere.

> 
> > 
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> 
> Reviewed-by: Marijn Suijten <marijn.suijten@...ainline.org>
> 

-- 
With best wishes
Dmitry