This is a note to let you know that I've just added the patch titled
qxl: alloc & use shadow for dumb buffers
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: qxl-alloc-use-shadow-for-dumb-buffers.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 62676d10b483a2ff6e8b08c5e7c7d63a831343f5 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann kraxel@redhat.com Date: Thu, 19 Oct 2017 08:21:50 +0200 Subject: qxl: alloc & use shadow for dumb buffers
From: Gerd Hoffmann kraxel@redhat.com
commit 62676d10b483a2ff6e8b08c5e7c7d63a831343f5 upstream.
This patch changes the way the primary surface is used for dumb framebuffers. Instead of configuring the bo itself as primary surface a shadow bo is created and used instead. Framebuffers can share the shadow bo in case they have the same format and resolution.
On atomic plane updates we don't have to update the primary surface in case we pageflip from one framebuffer to another framebuffer which shares the same shadow. This in turn avoids the flicker caused by the primary-destroy + primary-create cycle, which is very annonying when running wayland on qxl.
The qxl driver never actually writes to the shadow bo. It sends qxl blit commands which update it though, and the spice server might actually execute them (and thereby write to the shadow) in case the local rendering is kicked for some reason. This happens for example in case qemu is asked to write out a dump of the guest display (screendump monitor command).
Signed-off-by: Gerd Hoffmann kraxel@redhat.com Reviewed-by: Dave Airlie airlied@redhat.com Link: http://patchwork.freedesktop.org/patch/msgid/20171019062150.28090-3-kraxel@r... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/qxl/qxl_cmd.c | 6 +++- drivers/gpu/drm/qxl/qxl_display.c | 49 +++++++++++++++++++++++++++++++++++--- drivers/gpu/drm/qxl/qxl_drv.h | 2 + drivers/gpu/drm/qxl/qxl_dumb.c | 1 4 files changed, 54 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/qxl/qxl_cmd.c +++ b/drivers/gpu/drm/qxl/qxl_cmd.c @@ -388,7 +388,11 @@ void qxl_io_create_primary(struct qxl_de create->width = bo->surf.width; create->height = bo->surf.height; create->stride = bo->surf.stride; - create->mem = qxl_bo_physical_address(qdev, bo, offset); + if (bo->shadow) { + create->mem = qxl_bo_physical_address(qdev, bo->shadow, offset); + } else { + create->mem = qxl_bo_physical_address(qdev, bo, offset); + }
QXL_INFO(qdev, "%s: mem = %llx, from %p\n", __func__, create->mem, bo->kptr); --- a/drivers/gpu/drm/qxl/qxl_display.c +++ b/drivers/gpu/drm/qxl/qxl_display.c @@ -305,7 +305,9 @@ static const struct drm_crtc_funcs qxl_c void qxl_user_framebuffer_destroy(struct drm_framebuffer *fb) { struct qxl_framebuffer *qxl_fb = to_qxl_framebuffer(fb); + struct qxl_bo *bo = gem_to_qxl_bo(qxl_fb->obj);
+ WARN_ON(bo->shadow); drm_gem_object_unreference_unlocked(qxl_fb->obj); drm_framebuffer_cleanup(fb); kfree(qxl_fb); @@ -508,6 +510,7 @@ static void qxl_primary_atomic_update(st .x2 = qfb->base.width, .y2 = qfb->base.height }; + bool same_shadow = false;
if (old_state->fb) { qfb_old = to_qxl_framebuffer(old_state->fb); @@ -519,15 +522,23 @@ static void qxl_primary_atomic_update(st if (bo == bo_old) return;
+ if (bo_old && bo_old->shadow && bo->shadow && + bo_old->shadow == bo->shadow) { + same_shadow = true; + } + if (bo_old && bo_old->is_primary) { - qxl_io_destroy_primary(qdev); + if (!same_shadow) + qxl_io_destroy_primary(qdev); bo_old->is_primary = false; }
if (!bo->is_primary) { - qxl_io_create_primary(qdev, 0, bo); + if (!same_shadow) + qxl_io_create_primary(qdev, 0, bo); bo->is_primary = true; } + qxl_draw_dirty_fb(qdev, qfb, bo, 0, 0, &norect, 1, 1); }
@@ -681,8 +692,9 @@ static void qxl_cursor_atomic_disable(st static int qxl_plane_prepare_fb(struct drm_plane *plane, struct drm_plane_state *new_state) { + struct qxl_device *qdev = plane->dev->dev_private; struct drm_gem_object *obj; - struct qxl_bo *user_bo; + struct qxl_bo *user_bo, *old_bo = NULL; int ret;
if (!new_state->fb) @@ -691,6 +703,32 @@ static int qxl_plane_prepare_fb(struct d obj = to_qxl_framebuffer(new_state->fb)->obj; user_bo = gem_to_qxl_bo(obj);
+ if (plane->type == DRM_PLANE_TYPE_PRIMARY && + user_bo->is_dumb && !user_bo->shadow) { + if (plane->state->fb) { + obj = to_qxl_framebuffer(plane->state->fb)->obj; + old_bo = gem_to_qxl_bo(obj); + } + if (old_bo && old_bo->shadow && + user_bo->gem_base.size == old_bo->gem_base.size && + plane->state->crtc == new_state->crtc && + plane->state->crtc_w == new_state->crtc_w && + plane->state->crtc_h == new_state->crtc_h && + plane->state->src_x == new_state->src_x && + plane->state->src_y == new_state->src_y && + plane->state->src_w == new_state->src_w && + plane->state->src_h == new_state->src_h && + plane->state->rotation == new_state->rotation && + plane->state->zpos == new_state->zpos) { + drm_gem_object_get(&old_bo->shadow->gem_base); + user_bo->shadow = old_bo->shadow; + } else { + qxl_bo_create(qdev, user_bo->gem_base.size, + true, true, QXL_GEM_DOMAIN_VRAM, NULL, + &user_bo->shadow); + } + } + ret = qxl_bo_pin(user_bo, QXL_GEM_DOMAIN_CPU, NULL); if (ret) return ret; @@ -715,6 +753,11 @@ static void qxl_plane_cleanup_fb(struct obj = to_qxl_framebuffer(old_state->fb)->obj; user_bo = gem_to_qxl_bo(obj); qxl_bo_unpin(user_bo); + + if (user_bo->shadow && !user_bo->is_primary) { + drm_gem_object_put_unlocked(&user_bo->shadow->gem_base); + user_bo->shadow = NULL; + } }
static const uint32_t qxl_cursor_plane_formats[] = { --- a/drivers/gpu/drm/qxl/qxl_drv.h +++ b/drivers/gpu/drm/qxl/qxl_drv.h @@ -113,6 +113,8 @@ struct qxl_bo { /* Constant after initialization */ struct drm_gem_object gem_base; bool is_primary; /* is this now a primary surface */ + bool is_dumb; + struct qxl_bo *shadow; bool hw_surf_alloc; struct qxl_surface surf; uint32_t surface_id; --- a/drivers/gpu/drm/qxl/qxl_dumb.c +++ b/drivers/gpu/drm/qxl/qxl_dumb.c @@ -63,6 +63,7 @@ int qxl_mode_dumb_create(struct drm_file &handle); if (r) return r; + qobj->is_dumb = true; args->pitch = pitch; args->handle = handle; return 0;
Patches currently in stable-queue which might be from kraxel@redhat.com are
queue-4.14/drm-qxl-reapply-cursor-after-resetting-primary.patch queue-4.14/qxl-alloc-use-shadow-for-dumb-buffers.patch