kernel/linux.git/drivers/gpu/drm/drm_panic.c, branch v7.0-rc7

drm/panic: Fix expected string for QR_CODE in drm_panic_type_map

2026-01-09T08:53:27+00:00

The help text of CONFIG_DRM_PANIC_SCREEN_QR_CODE documents the expected value to CONFIG_DRM_PANIC_SCREEN as "qr_code" but drm_panic_type_map checks for "qr". Adjust drm_panic_type_map and the module description to match so that existing configurations do not stop working. Fixes: e85e9ccf3f84 ("drm/panic: Report invalid or unsupported panic modes") Signed-off-by: Nathan Chancellor Reviewed-by: Tvrtko Ursulin Reviewed-by: Jocelyn Falempe Signed-off-by: Tvrtko Ursulin Link: https://lore.kernel.org/r/20260105-drm_panic-handle-invalid-drm_panic_screen-v1-2-55228bd4b0f8@kernel.org

drm/panic: Ensure drm_panic_type is initialized to a valid value

2026-01-09T08:53:27+00:00

If a user has set an invalid CONFIG_DRM_PANIC_SCREEN value (such as "qr_code" without CONFIG_DRM_PANIC_SCREEN_QR_CODE=y due to missing or incorrect Rust dependencies), there is a panic when accessing /sys/module/drm/parameters/panic_screen: [ 12.218375] BUG: unable to handle page fault for address: 0000000796dd8818 [ 12.219737] #PF: supervisor read access in kernel mode ... [ 12.227167] RIP: 0010:drm_panic_type_get+0x1b/0x30 If drm_panic_type_set() does not find a valid drm_panic_type enumeration in drm_panic_type_map based on the provided value, it does not change drm_panic_type from the default -1 value, which is not a valid index for accessing drm_panic_type_map in drm_panic_type_get(), resulting in the crash. Validate the value of CONFIG_DRM_PANIC_SCREEN at boot time via the return value of drm_panic_type_set() in drm_panic_init() and explicitly fall back to the default of "user" with a message to the user so that they can adjust their configuration or fix missing dependencies. [ 0.800697] Unsupported value for CONFIG_DRM_PANIC_SCREEN ('qr_code'), falling back to 'user'... Fixes: e85e9ccf3f84 ("drm/panic: Report invalid or unsupported panic modes") Signed-off-by: Nathan Chancellor Reviewed-by: Tvrtko Ursulin Reviewed-by: Jocelyn Falempe Signed-off-by: Tvrtko Ursulin Link: https://lore.kernel.org/r/20260105-drm_panic-handle-invalid-drm_panic_screen-v1-1-55228bd4b0f8@kernel.org

drm/panic: Add kunit tests for drm_panic

2026-01-05T09:03:41+00:00

Add kunit tests for drm_panic. They check that drawing the panic screen doesn't crash, but they don't check the correctness of the resulting image. Reviewed-by: Maxime Ripard Link: https://patch.msgid.link/20251216082524.115980-3-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe

drm/panic: Rename draw_panic_static_* to draw_panic_screen_*

2026-01-05T08:59:13+00:00

I called them "static" because the panic screen is drawn only once, but this can be confused with the static meaning in C. Also remove some unnecessary braces in draw_panic_dispatch(). No functionnal change. Reviewed-by: Javier Martinez Canillas Link: https://patch.msgid.link/20251216082524.115980-2-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe

drm/panic: avoid WARN when checking format support

2025-12-19T22:06:41+00:00

Use drm_draw_can_convert_from_xrgb8888() instead of drm_draw_color_from_xrgb8888() while checking if a color format is usable. This avoids a WARN in case the first format is not usable. Reviewed-by: Jocelyn Falempe Signed-off-by: Francesco Valla Link: https://patch.msgid.link/20251217-drm_draw_conv_check-v3-3-15b6f8bc1cbc@valla.it Signed-off-by: Jocelyn Falempe

Merge drm/drm-next into drm-misc-next

2025-12-15T08:27:39+00:00

Let's kickstart the v6.20 (7.0?) release cycle. Signed-off-by: Maxime Ripard

drm/panic: Report invalid or unsupported panic modes

2025-11-28T15:20:34+00:00

Currently the user can write anything into the drm.panic_screen modparam, either at runtime via sysfs, or as a kernel boot time argument. Invalid strings will be silently accepted and ignored at use time by defaulting to the 'user' panic mode. Let instead add some validation in order to have immediate feedback when something has been mistyped, or not compiled in. For example during kernel boot: Booting kernel: `bsod' invalid for parameter `drm.panic_screen' Or at runtime: # echo -n bsod > /sys/module/drm/parameters/panic_screen -bash: echo: write error: Invalid argument Change of behavior is that when invalid mode is attempted to be configured, currently the code will default to the 'user' mode, while with this change the code will ignore it, and default to the mode set at kernel build time via CONFIG_DRM_PANIC_SCREEN. While at it lets also fix the module parameter description to include all compiled in modes. Signed-off-by: Tvrtko Ursulin Cc: Jocelyn Falempe Cc: Javier Martinez Canillas Reviewed-by: Javier Martinez Canillas Reviewed-by: Jocelyn Falempe Signed-off-by: Tvrtko Ursulin Link: https://lore.kernel.org/r/20251127090349.92717-1-tvrtko.ursulin@igalia.com

drm/panic: Fix 24bit pixel crossing page boundaries

2025-10-21T09:28:03+00:00

When using page list framebuffer, and using RGB888 format, some pixels can cross the page boundaries, and this case was not handled, leading to writing 1 or 2 bytes on the next virtual address. Add a check and a specific function to handle this case. Fixes: c9ff2808790f0 ("drm/panic: Add support to scanout buffer as array of pages") Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20251009122955.562888-7-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe

drm/panic: Fix divide by 0 if the screen width < font width

2025-10-21T09:28:03+00:00

In the unlikely case that the screen is tiny, and smaller than the font width, it leads to a divide by 0: draw_line_with_wrap() chars_per_row = sb->width / font->width = 0 line_wrap.len = line->len % chars_per_row; This will trigger a divide by 0 Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20251009122955.562888-6-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe

drm/panic: Fix kmsg text drawing rectangle

2025-10-21T09:28:03+00:00

The rectangle height was larger than the screen size. This has no real impact. Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20251009122955.562888-5-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe