On 08/01/2024 11:20, Maxime Ripard wrote:
Hi, On Thu, Jan 04, 2024 at 05:00:49PM +0100, Jocelyn Falempe wrote:This was initialy done for imx6, but should work on most drivers using drm_fb_dma_helper. Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx> --- drivers/gpu/drm/drm_fb_dma_helper.c | 55 +++++++++++++++++++++++++++++ include/drm/drm_fb_dma_helper.h | 4 +++ 2 files changed, 59 insertions(+) diff --git a/drivers/gpu/drm/drm_fb_dma_helper.c b/drivers/gpu/drm/drm_fb_dma_helper.c index 3b535ad1b07c..caed2935df4f 100644 --- a/drivers/gpu/drm/drm_fb_dma_helper.c +++ b/drivers/gpu/drm/drm_fb_dma_helper.c @@ -15,6 +15,7 @@ #include <drm/drm_framebuffer.h> #include <drm/drm_gem_dma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_panic.h> #include <drm/drm_plane.h> #include <linux/dma-mapping.h> #include <linux/module.h> @@ -148,3 +149,57 @@ void drm_fb_dma_sync_non_coherent(struct drm_device *drm, } } EXPORT_SYMBOL_GPL(drm_fb_dma_sync_non_coherent); + +#if defined(CONFIG_DRM_PANIC) +/** + * @dev: DRM device + * @drm_scanout_buffer: scanout buffer for the panic handler + * Returns: 0 or negative error code + * + * Generic get_scanout_buffer() implementation, for drivers that uses the + * drm_fb_dma_helper. + */ +int drm_panic_gem_get_scanout_buffer(struct drm_device *dev, + struct drm_scanout_buffer *sb) +{ + struct drm_plane *plane; + struct drm_gem_dma_object *dma_obj; + struct drm_framebuffer *fb; + + drm_for_each_primary_visible_plane(plane, dev) { + fb = plane->state->fb; + /* Only support linear modifier */ + if (fb->modifier != DRM_FORMAT_MOD_LINEAR) + continue; + + /* Check if color format is supported */ + if (!drm_panic_is_format_supported(fb->format->format)) + continue; + + dma_obj = drm_fb_dma_get_gem_obj(fb, 0); + + /* Buffer should be accessible from the CPU */ + if (dma_obj->base.import_attach) + continue; + + /* Buffer should be already mapped to CPU */ + if (!dma_obj->vaddr) + continue; + + iosys_map_set_vaddr(&sb->map, dma_obj->vaddr); + sb->format = fb->format; + sb->height = fb->height; + sb->width = fb->width; + sb->pitch = fb->pitches[0]; + return 0; + } + return -ENODEV; +} +#else +int drm_panic_gem_get_scanout_buffer(struct drm_device *dev, + struct drm_scanout_buffer *sb) +{ + return 0; +} +#endif +EXPORT_SYMBOL(drm_panic_gem_get_scanout_buffer);Looks much better, thanks :) I think we should be more vocal about the failure cases too. Maybe log it through warn/pr_crit or whatever so that at least we have an idea what went wrong in a post mortem.
Thanks for the review. Yes I can add an error message when it fails to find a scanout buffer.
Maxime
-- Jocelyn
