On Wed, Jul 17, 2024 at 10:48:40AM +0200, Jocelyn Falempe wrote:
> This is required to avoid conflict between DRM_PANIC, and fbcon. If
> a drm device already handle panic with drm_panic, it should set
> the skip_panic field in fb_info, so that fbcon will stay quiet, and
> not overwrite the panic_screen.
>
> Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_fb_helper.c | 2 ++
> drivers/video/fbdev/core/fbcon.c | 7 ++++++-
> include/linux/fb.h | 1 +
> 3 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index e2e19f49342e..3662d664d8f9 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -40,6 +40,7 @@
> #include <drm/drm_fourcc.h>
> #include <drm/drm_framebuffer.h>
> #include <drm/drm_modeset_helper_vtables.h>
> +#include <drm/drm_panic.h>
> #include <drm/drm_print.h>
> #include <drm/drm_vblank.h>
>
> @@ -524,6 +525,7 @@ struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
> fb_helper->info = info;
> info->skip_vt_switch = true;
>
> + info->skip_panic = drm_panic_is_enabled(fb_helper->dev);
> return info;
>
> err_release:
Bit a bikeshed, but I'd split this patch out since it's for drm's fbdev
emulation, not the fbcon core code. With that:
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
> index 3f7333dca508..498d9c07df80 100644
> --- a/drivers/video/fbdev/core/fbcon.c
> +++ b/drivers/video/fbdev/core/fbcon.c
> @@ -270,12 +270,17 @@ static int fbcon_get_rotate(struct fb_info *info)
> return (ops) ? ops->rotate : 0;
> }
>
> +static bool fbcon_skip_panic(struct fb_info *info)
> +{
> + return (info->skip_panic && unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID));
> +}
> +
> static inline int fbcon_is_inactive(struct vc_data *vc, struct fb_info *info)
> {
> struct fbcon_ops *ops = info->fbcon_par;
>
> return (info->state != FBINFO_STATE_RUNNING ||
> - vc->vc_mode != KD_TEXT || ops->graphics);
> + vc->vc_mode != KD_TEXT || ops->graphics || fbcon_skip_panic(info));
> }
>
> static int get_color(struct vc_data *vc, struct fb_info *info,
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index db7d97b10964..865dad03e73e 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -510,6 +510,7 @@ struct fb_info {
> void *par;
>
> bool skip_vt_switch; /* no VT switch on suspend/resume required */
> + bool skip_panic; /* Do not write to the fb after a panic */
> };
>
> /* This will go away
> --
> 2.45.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
