Hi, On 19/09/2019 05:30, jsa...@codeaurora.org wrote: > Hello All, > > I bumped into the below check [1] enforced in drm_framebuffer creation which > checks the requested framebuffer width/height parameters against the drm mode > config width/height limits. As I understand, drm_mode_config: min/max > width/height indicate the upper and lower bounds of the display panel > (drm_connector) resolutions the DRM device can support. But the pixel > processing pipeline can apply cropping/scaling transformations on much larger > input framebuffers and flip the buffers within the display resolution. Such > configurations are very common and the final resolution will be still within > drm_mode_config bounds. So I believe the checks should be relaxed / removed > from the drm_framebuffer creation api’s. > > > > If my understanding is incorrect, could somehow explain the motivation behind > having these checks here?
I already reported this a few months ago, here is the log of the discussion : https://patchwork.kernel.org/patch/10625707/ TL;DR it should be removed but these checks should be moved to control max screen size in atomic_commit paths. I planned to fix this, but haven't found time yet... Neil > > > > Thanks and Regards, > > Jeykumar S. > > > > [1] > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/drm_framebuffer.c?h=v5.3#n303 > > > > *struct*drm_framebuffer * > > *drm_internal_framebuffer_create*(*struct*drm_device *dev, > > *const**struct*drm_mode_fb_cmd2 *r, > > *struct*drm_file *file_priv) > > { > > /* snip */ > > > > *if*((config->min_width > r->width) || (r->width > > config->max_width)) { > > DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= > %d\n", > > r->width, config->min_width, config->max_width); > > *return*ERR_PTR(-EINVAL); > > } > > *if*((config->min_height > r->height) || (r->height > > config->max_height)) { > > DRM_DEBUG_KMS("bad framebuffer height %d, should be >= %d && > <= %d\n", > > r->height, config->min_height, config->max_height); > > *return*ERR_PTR(-EINVAL); > > } > > /* snip */ > > } > > > > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
