Re: [PATCH RFC v2 0/6] ARM: qcom: initial Nexus 5 display support

From: Brian Masney <masneyb-1iNe0GrtECGEi8DpZVb4nw@public.gmane.org>
To: Jeffrey Hugo <jeffrey.l.hugo-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Jonathan Marek <jonathan-eSc4qw6YbEQ@public.gmane.org>,
	Dave Airlie <airlied-cv59FeDIM0c@public.gmane.org>,
	MSM <linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Linus Walleij
	<linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
	"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"open list:DRM PANEL DRIVERS"
	<dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>,
	Rob Clark <robdclark-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Daniel Vetter <daniel-/w4YWyX8dFk@public.gmane.org>,
	freedreno-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
	Sean Paul <sean-p7yTbzM4H96eqtR555YLDQ@public.gmane.org>
Subject: Re: [PATCH RFC v2 0/6] ARM: qcom: initial Nexus 5 display support
Date: Wed, 29 May 2019 06:28:22 -0400	[thread overview]
Message-ID: <20190529102822.GA15027@basecamp> (raw)
In-Reply-To: <CAOCk7NpC93ACr4jFm7SBOKSvFJSDhq2byX6BAYPX29BuYEkWnQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

[-- Attachment #1: Type: text/plain, Size: 2048 bytes --]

On Tue, May 28, 2019 at 08:53:49PM -0600, Jeffrey Hugo wrote:
> On Tue, May 28, 2019 at 8:46 PM Brian Masney <masneyb-1iNe0GrtECGEi8DpZVb4nw@public.gmane.org> wrote:
> >
> > On Tue, May 28, 2019 at 07:42:19PM -0600, Jeffrey Hugo wrote:
> > > > > Do you know if the nexus 5 has a video or command mode panel?  There
> > > > > is some glitchyness with vblanks and command mode panels.
> > > >
> > > > Its in command mode. I know this because I see two 'pp done time out'
> > > > messages, even on 4.17. Based on my understanding, the ping pong code is
> > > > only applicable for command mode panels.
> > >
> > > Actually, the ping pong element exists in both modes, but 'pp done
> > > time out' is a good indicator that it is command mode.
> > >
> > > Are you also seeing vblank timeouts?
> >
> > Yes, here's a snippet of the first one.
> >
> > [    2.556014] WARNING: CPU: 0 PID: 5 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x288/0x290
> > [    2.556020] [CRTC:49:crtc-0] vblank wait timed out
> > [    2.556023] Modules linked in:
> > [    2.556034] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.2.0-rc1-00178-g72c3c1fd5f86-dirty #426
> > [    2.556038] Hardware name: Generic DT based system
> > [    2.556056] Workqueue: events deferred_probe_work_func
> > ...
> >
> > > Do you have busybox?
> > >
> > > Can you run -
> > > sudo busybox devmem 0xFD900614
> > > sudo busybox devmem 0xFD900714
> > > sudo busybox devmem 0xFD900814
> > > sudo busybox devmem 0xFD900914
> > > sudo busybox devmem 0xFD900A14
> >
> > # busybox devmem 0xFD900614
> > 0x00020020
> 
> Ok, so CTL_0 path, command mode, ping pong 0, with the output going to DSI 1.
> 
> Next one please:
> 
> busybox devmem 0xFD912D30

It's 0x00000000 on mainline and 4.17. I used the following script to
dump the entire mdp5 memory region and attached the dump from 4.17 and
5.2rc1.

	POS="0XFD900100"
	while [ "${POS}" != "0XFD925000" ] ; do
		echo -n "${POS} = "
		busybox devmem "${POS}" 
		POS=$(printf '%#X' "$((${POS} + 4))")
	done

Brian

[-- Attachment #2: mdp-memory-dump-4.17.txt.gz --]
[-- Type: application/gzip, Size: 102937 bytes --]

[-- Attachment #3: mdp-memory-dump-5.2rc1.txt.gz --]
[-- Type: application/gzip, Size: 103222 bytes --]

[-- Attachment #4: Type: text/plain, Size: 159 bytes --]

_______________________________________________
Freedreno mailing list
Freedreno@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/freedreno