Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <1677774797-31063-1-git-send-email-quic_vpolimer@quicinc.com>
 <1677774797-31063-15-git-send-email-quic_vpolimer@quicinc.com>
 <20230326162723.3lo6pnsfdwzsvbhj@ripper> <20230326163556.iesjkoh3nw3iwvf2@ripper>
 <CAE-0n520ypTRNT1X6kZ8o_Z+DN_68qwqZc1wZGMwsFqV5naktw@mail.gmail.com>
 <BN0PR02MB81736AFC01FB13F1640068CEE4899@BN0PR02MB8173.namprd02.prod.outlook.com>
 <CAD=FV=UjHiEk==KAhbx6QFW++69vDAM44sw-b2MGcJ7NsfbF-A@mail.gmail.com>
In-Reply-To: <CAD=FV=UjHiEk==KAhbx6QFW++69vDAM44sw-b2MGcJ7NsfbF-A@mail.gmail.com>
From:   Doug Anderson <dianders@chromium.org>
Date:   Thu, 30 Mar 2023 07:23:38 -0700
Message-ID: <CAD=FV=V7UoA5jP-ANFMNzm3oLbYmT73uDnqs0oKHKb16-NcULg@mail.gmail.com>
Subject: Re: [PATCH v14 14/14] drm/msm/dp: set self refresh aware based on PSR support
To:     Vinod Polimera <vpolimer@qti.qualcomm.com>
Cc:     Stephen Boyd <swboyd@chromium.org>,
        Bjorn Andersson <andersson@kernel.org>,
        "Vinod Polimera (QUIC)" <quic_vpolimer@quicinc.com>,
        "robdclark@gmail.com" <robdclark@gmail.com>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>,
        "freedreno@lists.freedesktop.org" <freedreno@lists.freedesktop.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Kalyan Thota (QUIC)" <quic_kalyant@quicinc.com>,
        "dmitry.baryshkov@linaro.org" <dmitry.baryshkov@linaro.org>,
        "Kuogee Hsieh (QUIC)" <quic_khsieh@quicinc.com>,
        "Vishnuvardhan Prodduturi (QUIC)" <quic_vproddut@quicinc.com>,
        "Bjorn Andersson (QUIC)" <quic_bjorande@quicinc.com>,
        "Abhinav Kumar (QUIC)" <quic_abhinavk@quicinc.com>,
        "Sankeerth Billakanti (QUIC)" <quic_sbillaka@quicinc.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi,

On Wed, Mar 29, 2023 at 8:47=E2=80=AFAM Doug Anderson <dianders@chromium.or=
g> wrote:
>
> Hi,
>
> On Wed, Mar 29, 2023 at 8:16=E2=80=AFAM Vinod Polimera
> <vpolimer@qti.qualcomm.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: Stephen Boyd <swboyd@chromium.org>
> > > Sent: Monday, March 27, 2023 9:58 PM
> > > To: Bjorn Andersson <andersson@kernel.org>; Vinod Polimera (QUIC)
> > > <quic_vpolimer@quicinc.com>
> > > Cc: dri-devel@lists.freedesktop.org; linux-arm-msm@vger.kernel.org;
> > > freedreno@lists.freedesktop.org; devicetree@vger.kernel.org; linux-
> > > kernel@vger.kernel.org; robdclark@gmail.com; dianders@chromium.org;
> > > Kalyan Thota (QUIC) <quic_kalyant@quicinc.com>;
> > > dmitry.baryshkov@linaro.org; Kuogee Hsieh (QUIC)
> > > <quic_khsieh@quicinc.com>; Vishnuvardhan Prodduturi (QUIC)
> > > <quic_vproddut@quicinc.com>; Bjorn Andersson (QUIC)
> > > <quic_bjorande@quicinc.com>; Abhinav Kumar (QUIC)
> > > <quic_abhinavk@quicinc.com>; Sankeerth Billakanti (QUIC)
> > > <quic_sbillaka@quicinc.com>
> > > Subject: Re: [PATCH v14 14/14] drm/msm/dp: set self refresh aware bas=
ed
> > > on PSR support
> > >
> > > Quoting Bjorn Andersson (2023-03-26 09:35:56)
> > > > On Sun, Mar 26, 2023 at 09:27:23AM -0700, Bjorn Andersson wrote:
> > > > > On Thu, Mar 02, 2023 at 10:03:17PM +0530, Vinod Polimera wrote:
> > > > > > For the PSR to kick in, self_refresh_aware has to be set.
> > > > > > Initialize it based on the PSR support for the eDP interface.
> > > > > >
> > > > >
> > > > > When I boot my sc8280xp devices (CRD and X13s) to console with th=
is
> > > > > patch included I get a login prompt, and then there are no more s=
creen
> > > > > updates.
> > > > >
> > > > > Switching virtual terminal (ctrl+alt+fN) causes the screen to red=
raw.
> > > > >
> > > > > Blindly login in and launching Wayland works and from then on scr=
een
> > > > > updates works as expected.
> > > > >
> > > > > Switching from Wayland to another virtual terminal causes the pro=
blem
> > > to
> > > > > re-appear, no updates after the initial refresh, switching back g=
o the
> > > > > Wayland-terminal crashed the machine.
> > > > >
> > > >
> > > > Also, trying to bring the eDP-screen back from DPMS gives me:
> > > >
> > > > <3>[ 2355.218099] [drm:dp_catalog_ctrl_set_pattern_state_bit [msm]]
> > > *ERROR* set state_bit for link_train=3D1 failed
> > > > <3>[ 2355.218926] [drm:dp_ctrl_setup_main_link [msm]] *ERROR* link
> > > training #1 failed. ret=3D-110
> > > > <3>[ 2355.262859] [drm:dp_catalog_ctrl_set_pattern_state_bit [msm]]
> > > *ERROR* set state_bit for link_train=3D1 failed
> > > > <3>[ 2355.263600] [drm:dp_ctrl_setup_main_link [msm]] *ERROR* link
> > > training #1 failed. ret=3D-110
> > > > <3>[ 2355.305211] [drm:dp_catalog_ctrl_set_pattern_state_bit [msm]]
> > > *ERROR* set state_bit for link_train=3D1 failed
> > > > <3>[ 2355.305955] [drm:dp_ctrl_setup_main_link [msm]] *ERROR* link
> > > training #1 failed. ret=3D-110
> > > > <3>[ 2355.345250] [drm:dp_catalog_ctrl_set_pattern_state_bit [msm]]
> > > *ERROR* set state_bit for link_train=3D1 failed
> > > > <3>[ 2355.346026] [drm:dp_ctrl_setup_main_link [msm]] *ERROR* link
> > > training #1 failed. ret=3D-110
> > > > <3>[ 2355.405650] [drm:dp_display_process_hpd_high [msm]] *ERROR*
> > > failed to complete DP link training
> > > > <3>[ 2355.668988]
> > > [drm:dpu_encoder_phys_vid_wait_for_commit_done:488] [dpu
> > > error]vblank timeout
> > > > <3>[ 2355.669030] [drm:dpu_kms_wait_for_commit_done:510] [dpu
> > > error]wait for commit done returned -110
> > > > <3>[ 2355.699989] [drm:dpu_encoder_frame_done_timeout:2398] [dpu
> > > error]enc35 frame done timeout
> > > >
> > > > And then the machine just resets.
> > > >
> > >
> > > I saw similar behavior on ChromeOS after we picked the PSR patches in=
to
> > > our kernel. I suspect it's the same problem. I switched back and fort=
h
> > > between VT2 and the OOBE screen with ctrl+alt+forward and that showed
> > > what I typed on the virtual terminal after switching back and forth.
> > > It's like the redraw only happens once on the switch and never again.=
 I
> > > switched back and forth enough times that it eventually crashed the
> > > kernel and rebooted. This was on CRD (sc7280-herobrine-crd.dts).
> > >
> > > There's an animation on the OOBE screen that is working though, so
> > > perhaps PSR is working with the chrome compositor but not the virtual
> > > terminal? I haven't investigated.
> >
> > I was able to reproduce the issue where in virtual terminal, I don't se=
e any screen refresh despite typing in.
> > In the VT mode, I see that PSR is entered, but despite typing in there =
are no atomic commits triggered, hence the last buffer was always refreshed=
.
> >
> > Queries from my side to Rob & Doug:
> > 1) In VT mode, does the framework operates in single buffer mode withou=
t any commit for new updates ?
> > 2) if above is true then, how does driver know if the framework operate=
s in single buffer mode, to make any appropriate action
> > 3) what is the expected behavior with the driver here ? should it retur=
n atomic_check failure, for single buffer mode operation or, it should exit=
 PSR ?
> > 4) is there any HINT passed down to the driver so that we can bank on i=
t and act accordingly?
>
> I haven't looked at this detail about PSR before, and I left my
> PSR-enabled device at home so I can't easily test this right now. That
> being said, from a bit of searching I would guess that
> msm_framebuffer_dirtyfb() is somehow involved here. Are things better
> if you get rid of the test against 'msm_fb->dirtyfb'?
>
> I at least used ftrace to confirm that on a different device
> msm_framebuffer_dirtyfb() is not called during normal ChromeOS usage
> but it _is_ called in VT2 usage.

Indeed, I can confirm that if I comment out the test in
msm_framebuffer_dirtyfb() and just call straight through to
drm_atomic_helper_dirtyfb() that typing on VT2 works fine.

...so presumably you need to figure out how to get "dirtyfb" set
properly when you have a PSR-enabled panel or maybe whenever the panel
enters PSR mode?

-Doug