Re: [PATCH RFC drm-next 0/1] Add support for drm_panic

[Ryosuke Yasuoka]

On Wed, Apr 2, 2025 at 6:45 PM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
>
> Hi
>
> Am 02.04.25 um 10:43 schrieb Ryosuke Yasuoka:
> > This patch adds drm_panic support for hyperv-drm driver. This function
> > works but it's still needed to brush up. Let me hear your opinions.
> >
> > Once kernel panic occurs we expect to see a panic screen. However, to
> > see the screen, I need to close/re-open the graphic console client
> > window. As the panic screen shows correctly in the small preview
> > window in Hyper-V manager and debugfs API for drm_panic works correctly,
> > I think kernel needs to send signal to Hyper-V host that the console
> > client refreshes, but I have no idea what kind of signal is needed.
> >
> > This patch is tested on Hyper-V 2022.
> >
> > Ryosuke Yasuoka (1):
> >    drm/hyperv: Add support for drm_panic
> >
> >   drivers/gpu/drm/drm_simple_kms_helper.c     | 26 +++++++++++++
> >   drivers/gpu/drm/hyperv/hyperv_drm_modeset.c | 42 +++++++++++++++++++++
> >   include/drm/drm_simple_kms_helper.h         | 22 +++++++++++
>
> No changes to simple_kms_helper please. This is obsolete and should go
> away. Just put everything into hyperv_drm.

OK. Maybe it will work without any modification in simple_kms_helper if we can
call the pipe->funcs from draw_panic_plane() like drm_plane_helper_funcs.

Currently, the hyperv_drm is implemented with a simple display pipeline.
The pipeline control functions are in pipe->funcs and they will call via
drm_simple_kms_palne_helper_funcs. And these helper functions will
be called by drm_panic_plane().

Thank you for your comment.
Ryosuke

> Best regards
> Thomas
>
> >   3 files changed, 90 insertions(+)
> >
> >
> > base-commit: cf05922d63e2ae6a9b1b52ff5236a44c3b29f78c
>
> --
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Frankenstrasse 146, 90461 Nuernberg, Germany
> GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
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>