drm/vc4: module dysfunctional on Raspberry Pi 3B as of 5.18.0

[Maxime Ripard]

Hi Peter(s)

On Wed, Jun 08, 2022 at 02:10:19PM +0100, Peter Robinson wrote:
> Hi Peter,
> 
> Adding Stefan and Maxime
> 
> > As of Linux 5.18.0, module vc4 apparently isn't working on Raspberry Pi
> > 3B any more.
> >
> > If a monitor is attached to the device, the boot messages show up as
> > usual, but right when KMS starts, the screen turns black. Similarly, the
> > screen also turns black when the module is blacklisted at boot time and
> > loaded from the running system.
> > The problem looks quite similar to the one posted some months ago in [1].

If I understand you properly, it results in a blank screen if the
monitor is connected, but the system is still responsive?

If so, it's a very different problem than the link you provided, since
it was occurring when no monitor was connected and resulted in a total
system hang.

> > Unfortunately, looking through systemd's journal didn't seem to yield
> > any real hint. Nevertheless, the results from grepping vc4 are
> 
> I'm seeing the same issue with vc4 on a RPi3 on 5.18.1 on Fedora so
> can confirm the regression. Maxime would know what might be up here?

I tested on 5.18 on my 3B and it works well. Could you paste your kernel
configuration and config.txt somewhere?

> > → 5.17.1
> >  > kernel: vc4-drm soc:gpu: bound 3f400000.hvs (ops vc4_hvs_ops [vc4])
> >  > kernel: rc rc0: vc4 as /devices/platform/soc/3f902000.hdmi/rc/rc0
> >  > kernel: input: vc4 as /devices/platform/soc/3f902000.hdmi/rc/rc0/input0
> >  > kernel: vc4-drm soc:gpu: bound 3f902000.hdmi (ops vc4_hdmi_ops [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f806000.vec (ops vc4_vec_ops [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f004000.txp (ops vc4_txp_ops [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f206000.pixelvalve (ops vc4_crtc_ops
> > [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f207000.pixelvalve (ops vc4_crtc_ops
> > [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f807000.pixelvalve (ops vc4_crtc_ops
> > [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3fc00000.v3d (ops vc4_v3d_ops [vc4])
> >  > kernel: fb0: switching to vc4 from simple
> >  > kernel: [drm] Initialized vc4 0.0.0 20140616 for soc:gpu on minor 0
> >  > kernel: vc4-drm soc:gpu: [drm] fb0: vc4drmfb frame buffer device
> >  > systemd-logind[338]: Watching system buttons on /dev/input/event0 (vc4)
> > → 5.18.0
> >  > kernel: fb0: switching to vc4 from simple
> >  > kernel: vc4-drm soc:gpu: bound 3f400000.hvs (ops vc4_hvs_ops [vc4])
> >  > kernel: rc rc0: vc4 as /devices/platform/soc/3f902000.hdmi/rc/rc0
> >  > kernel: input: vc4 as /devices/platform/soc/3f902000.hdmi/rc/rc0/input0
> >  > kernel: vc4-drm soc:gpu: bound 3f902000.hdmi (ops vc4_hdmi_ops [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f806000.vec (ops vc4_vec_ops [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f004000.txp (ops vc4_txp_ops [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f206000.pixelvalve (ops vc4_crtc_ops
> > [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f207000.pixelvalve (ops vc4_crtc_ops
> > [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3f807000.pixelvalve (ops vc4_crtc_ops
> > [vc4])
> >  > kernel: vc4-drm soc:gpu: bound 3fc00000.v3d (ops vc4_v3d_ops [vc4])
> >  > kernel: [drm] Initialized vc4 0.0.0 20140616 for soc:gpu on minor 0
> >  > kernel: vc4-drm soc:gpu: [drm] fb0: vc4drmfb frame buffer device
> >  > systemd-logind[337]: Watching system buttons on /dev/input/event0 (vc4)

Yeah, it doesn't look that different.

Maxime
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 228 bytes
Desc: not available
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20220608/a1aec5f3/attachment.sig>