Re: [PATCH 33/33] drm/panel-simple: Fix dotclock for LG ACX467AKM-7

Brian Masney
2020-03-04T07:47:54Z

On Tue, Mar 03, 2020 at 09:27:50PM -0500, Jonathan Marek wrote:
> modetest should be printing "freq: 60.0Hz", so definitely something wrong
> there. Though I guess you have another problem since I would expect the
> patch to drop it to 30 and not 13.5.
>
> (FYI glmark-x11 isn't vsynced which is why I specifically mentioned
> glmark-drm)

I tried compiling the drm variant and it was complaining about some
missing dependencies that I didn't see in Alpine Linux. I didn't try too
hard since I'm a bit short on time at this point since I'm starting a
new job on Monday and I have another side project that I want to finish
before then.

I suspect that the issue is caused by the introduction of the async
commit support in the MSM driver that introduced the ping/pong timeouts.
I'll try in a few weeks or so reverting those patches and see if that
affects the speed.

I'm still ok with Ville's patch going in given the existing slow state.
There's no clear path forward right now for the autocommit patch that I
linked to earlier in this thread. :(

Brian

>
> On 3/3/20 9:16 PM, Brian Masney wrote:
> > On Tue, Mar 03, 2020 at 08:04:05AM -0500, Jonathan Marek wrote:
> > > What Xorg prints doesn't mean anything. I don't think there will be errors
> > > in dmesg, you need to run something that does pageflips as fast as possible
> > > and see that the refresh rate is still 60. (modetest with -v, glmark-drm are
> > > examples)
> >
> > I assume that you mean modetest from
> > https://gitlab.freedesktop.org/mesa/drm/tree/master/tests/modetest ?
> > Here's the modeset connector information:
> >
> > id encoder status name size (mm) modes encoders
> > 32 31 connected DSI-1 62x110 1 31
> > modes:
> > index name refresh (Hz) hdisp hss hse htot vdisp vss vse vtot)
> > #0 1080x1920 71.71 1080 1082 1084 1086 1920 1922 1924 1926 150000
> > flags: ; type: preferred, driver
> >
> > And the page flip results...
> >
> > $ modetest -v -s 32:1080x1920
> > trying to open device 'msm'...done
> > setting mode 1080x1920-71.71Hz@XR24 on connectors 32, crtc 50
> > failed to set gamma: Function not implemented
> > freq: 13.50Hz
> > freq: 13.51Hz
> > freq: 13.51Hz
> >
> > It's the same results with and without Ville's patch.
> >
> > Here's the beginning of the glmark2 results with the x11-gl flavor:
> >
> > =======================================================
> > glmark2 2017.07
> > =======================================================
> > OpenGL Information
> > GL_VENDOR: freedreno
> > GL_RENDERER: FD330
> > GL_VERSION: 3.1 Mesa 20.0.0-devel
> > =======================================================
> > [build] use-vbo=false: FPS: 26 FrameTime: 38.462 ms
> > [build] use-vbo=true: FPS: 26 FrameTime: 38.462 ms
> > [texture] texture-filter=nearest: FPS: 26 FrameTime: 38.462 ms
> > [texture] texture-filter=linear: FPS: 26 FrameTime: 38.462 ms
> > [texture] texture-filter=mipmap: FPS: 27 FrameTime: 37.037 ms
> > [shading] shading=gouraud: FPS: 27 FrameTime: 37.037 ms
> > [shading] shading=blinn-phong-inf: FPS: 27 FrameTime: 37.037 ms
> > [shading] shading=phong: FPS: 27 FrameTime: 37.037 ms
> > [shading] shading=cel: FPS: 26 FrameTime: 38.462 ms
> > [bump] bump-render=high-poly: FPS: 27 FrameTime: 37.037 ms
> > [bump] bump-render=normals: FPS: 27 FrameTime: 37.037 ms
> > [bump] bump-render=height: FPS: 27 FrameTime: 37.037 ms
> > [effect2d] kernel=0,1,0;1,-4,1;0,1,0;: FPS: 25 FrameTime: 40.000 ms
> > [effect2d] kernel=1,1,1,1,1;1,1,1,1,1;1,1,1,1,1;: FPS: 26 FrameTime:
> > 38.462 ms
> > [pulsar] light=false:quads=5:texture=false: FPS: 26 FrameTime: 38.462 ms
> > [desktop] blur-radius=5:effect=blur:passes=1:separable=true:windows=4:
> > FPS: 26 FrameTime: 38.462 ms
> > [desktop] effect=shadow:windows=4: FPS: 27 FrameTime: 37.037 ms
> > ...
> >
> > Brian
> >
> >
> > >
> > > On 3/3/20 7:26 AM, Brian Masney wrote:
> > > > On Mon, Mar 02, 2020 at 10:36:54PM -0500, Jonathan Marek wrote:
> > > > > Another thing: did you verify that the panel still runs at 60hz (and not
> > > > > dropping frames to 30hz)? IIRC that was the behavior with lower clock.
> > > >
> > > > Yes, the panel is running at 60 HZ according to the Xorg log with
> > > > Ville's patch applied:
> > > >
> > > > modeset(0): Modeline "1080x1920"x60.0 125.50 1080 1082 1084 1086
> > > > 1920 1922 1924 1926 (115.6 kHz eP)
> > > >
> > > > I verified there's no underflow errors in dmesg.
> > > >
> > > > If I recall correctly, the clock speeds that was in your tree was set
> > > > too low for the gpu_opp_table (that wouldn't cause this issue), but I
> > > > seem to recall there were some other clock speed mismatches. The
> > > > bandwidth requests weren't set on the RPM as well, so maybe that
> > > > contributed to the problem. That's done upstream with the msm8974
> > > > interconnect driver:
> > > >
> > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/interconnect/qcom/msm8974.c
> > > >
> > > > There's a separate known issue with 'pp done time out' errors that
> > > > occur on the framebuffer that started upstream several months ago with
> > > > the introduction of async commit support in the MSM driver. I tried
> > > > working around this by enabling the autorefresh feature but it's not
> > > > fully working yet and I hit a dead end since there's no docs available
> > > > publicly for this. The grim details are at:
> > > >
> > > > https://lore.kernel.org/lkml/20191230020053.26016-2-masneyb@onstation.org/
> > > >
> > > > So I'm still OK with Ville's patch going in.
> > > >
> > > > Brian
> > > >
> > > >
> > > > >
> > > > > On 3/2/20 10:28 PM, Jonathan Marek wrote:
> > > > > >
> > > > > > On 3/2/20 10:13 PM, Brian Masney wrote:
> > > > > > > On Mon, Mar 02, 2020 at 03:48:22PM -0500, Jonathan Marek wrote:
> > > > > > > > Hi,
> > > > > > > >
> > > > > > > > This is a command mode panel and the the msm/mdp5 driver uses
> > > > > > > > the vrefresh
> > > > > > > > field for the actual refresh rate, while the dotclock field is
> > > > > > > > used for the
> > > > > > > > DSI clocks. The dotclock needed to be a bit higher than
> > > > > > > > necessary otherwise
> > > > > > > > the panel would not work.
> > > > > > > >
> > > > > > > > If you want to get rid of the separate clock/vrefresh fields there would
> > > > > > > > need to be some changes to msm driver.
> > > > > > > >
> > > > > > > > (note I hadn't made the patch with upstreaming in mind, the
> > > > > > > > 150000 value is
> > > > > > > > likely not optimal, just something that worked, this is something that
> > > > > > > > should have been checked with the downstream driver)
> > > > > > >
> > > > > > > Is this the right clock frequency in the downstream MSM 3.4 kernel that
> > > > > > > you're talking about?
> > > > > > >
> > > > > > > https://github.com/AICP/kernel_lge_hammerhead/blob/n7.1/arch/arm/mach-msm/clock-8974.c#L3326
> > > > > > >
> > > > > > >
> > > > > >
> > > > > > No, I'm talking about the DSI clock (the driver for it is in
> > > > > > drm/msm/dsi/). For a command mode panel the front/back porches aren't
> > > > > > relevant, but the dsi pixel/byte clock need to be a bit higher than
> > > > > > 1920x1080x60. Since 125498 is a little higher than 124416 that might be
> > > > > > enough (there is also rounding of the clock values to consider).
> > > > > >
> > > > > > > I don't see any obvious clock values in the downstream command mode
> > > > > > > panel configuration:
> > > > > > >
> > > > > > > https://github.com/AICP/kernel_lge_hammerhead/blob/n7.1/arch/arm/boot/dts/msm8974-hammerhead/msm8974-hammerhead-panel.dtsi#L591
> > > > > > >
> > > > > > >
> > > > > > > Anyways, I tried Ville's patch with the framebuffer, kmscube, and X11
> > > > > > > and everything appears to be working fine. You can add my Tested-by if
> > > > > > > you end up applying this.
> > > > > > >
> > > > > > > Tested-by: Brian Masney <masneyb@onstation.org>
> > > > > > >
> > > > > > > Brian
> > > > > > >
> > > > > > >
> > > > > > > > On 3/2/20 3:34 PM, Ville Syrjala wrote:
> > > > > > > > > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > > > > > >
> > > > > > > > > The currently listed dotclock disagrees with the currently
> > > > > > > > > listed vrefresh rate. Change the dotclock to match the vrefresh.
> > > > > > > > >
> > > > > > > > > Someone tell me which (if either) of the dotclock or vreresh is
> > > > > > > > > correct?
> > > > > > > > >
> > > > > > > > > Cc: Jonathan Marek <jonathan@marek.ca>
> > > > > > > > > Cc: Brian Masney <masneyb@onstation.org>
> > > > > > > > > Cc: Linus Walleij <linus.walleij@linaro.org>
> > > > > > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > > > > > > ---
> > > > > > > > >    drivers/gpu/drm/panel/panel-simple.c | 2 +-
> > > > > > > > >    1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > > > > >
> > > > > > > > > diff --git a/drivers/gpu/drm/panel/panel-simple.c
> > > > > > > > > b/drivers/gpu/drm/panel/panel-simple.c
> > > > > > > > > index b24fdf239440..f958d8dfd760 100644
> > > > > > > > > --- a/drivers/gpu/drm/panel/panel-simple.c
> > > > > > > > > +++ b/drivers/gpu/drm/panel/panel-simple.c
> > > > > > > > > @@ -3996,7 +3996,7 @@ static const struct panel_desc_dsi
> > > > > > > > > panasonic_vvx10f004b00 = {
> > > > > > > > >    };
> > > > > > > > >    static const struct drm_display_mode lg_acx467akm_7_mode = {
> > > > > > > > > -    .clock = 150000,
> > > > > > > > > +    .clock = 125498,
> > > > > > > > >        .hdisplay = 1080,
> > > > > > > > >        .hsync_start = 1080 + 2,
> > > > > > > > >        .hsync_end = 1080 + 2 + 2,
> > > > > > > > >