From f6bfc9afc7510cb5e6fbe0a17c507917b0120280 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Mon, 7 Jul 2025 15:11:55 +0200 Subject: drm/framebuffer: Acquire internal references on GEM handles MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Acquire GEM handles in drm_framebuffer_init() and release them in the corresponding drm_framebuffer_cleanup(). Ties the handle's lifetime to the framebuffer. Not all GEM buffer objects have GEM handles. If not set, no refcounting takes place. This is the case for some fbdev emulation. This is not a problem as these GEM objects do not use dma-bufs and drivers will not release them while fbdev emulation is running. Framebuffer flags keep a bit per color plane of which the framebuffer holds a GEM handle reference. As all drivers use drm_framebuffer_init(), they will now all hold dma-buf references as fixed in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers"). In the GEM framebuffer helpers, restore the original ref counting on buffer objects. As the helpers for handle refcounting are now no longer called from outside the DRM core, unexport the symbols. v3: - don't mix internal flags with mode flags (Christian) v2: - track framebuffer handle refs by flag - drop gma500 cleanup (Christian) Signed-off-by: Thomas Zimmermann Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") Reported-by: Bert Karwatzki Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/ Tested-by: Bert Karwatzki Tested-by: Mario Limonciello Tested-by: Borislav Petkov (AMD) Cc: Thomas Zimmermann Cc: Anusha Srivatsa Cc: Christian König Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Sumit Semwal Cc: "Christian König" Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: Reviewed-by: Christian König Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de --- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'drivers/gpu/drm/drm_gem_framebuffer_helper.c') diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c index 14a87788695d..6f72e7a0f427 100644 --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -99,7 +99,7 @@ void drm_gem_fb_destroy(struct drm_framebuffer *fb) unsigned int i; for (i = 0; i < fb->format->num_planes; i++) - drm_gem_object_handle_put_unlocked(fb->obj[i]); + drm_gem_object_put(fb->obj[i]); drm_framebuffer_cleanup(fb); kfree(fb); @@ -182,10 +182,8 @@ int drm_gem_fb_init_with_funcs(struct drm_device *dev, if (!objs[i]) { drm_dbg_kms(dev, "Failed to lookup GEM object\n"); ret = -ENOENT; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } - drm_gem_object_handle_get_unlocked(objs[i]); - drm_gem_object_put(objs[i]); min_size = (height - 1) * mode_cmd->pitches[i] + drm_format_info_min_pitch(info, i, width) @@ -195,22 +193,22 @@ int drm_gem_fb_init_with_funcs(struct drm_device *dev, drm_dbg_kms(dev, "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", objs[i]->size, min_size, i); - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); ret = -EINVAL; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } } ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); if (ret) - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; return 0; -err_gem_object_handle_put_unlocked: +err_gem_object_put: while (i > 0) { --i; - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); } return ret; } -- cgit v1.2.3