DRM drivers will be able to handle deferred I/O by themselves. So a driver will be able to use deferred I/O without an intermediate shadow buffer.
Prepare fbdev emulation by separating shadow buffers and deferred I/O from each other.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de --- drivers/gpu/drm/drm_fb_helper.c | 35 ++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index dd1d72d58b35..660ec5038c4e 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -660,6 +660,19 @@ static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper) fb->funcs->dirty; }
+static bool drm_fbdev_use_deferred_io(struct drm_fb_helper *fb_helper) +{ + struct drm_framebuffer *fb = fb_helper->fb; + + /* + * Any driver with damage handling requires deferred I/O to + * keep track of the updated screen areas. Drivers with shadow + * buffers need deferred I/O to forward screen updates to the + * buffer object. + */ + return fb->funcs->dirty || drm_fbdev_use_shadow_fb(fb_helper); +} + static void drm_fb_helper_damage(struct fb_info *info, u32 x, u32 y, u32 width, u32 height) { @@ -667,7 +680,7 @@ static void drm_fb_helper_damage(struct fb_info *info, u32 x, u32 y, struct drm_clip_rect *clip = &helper->damage_clip; unsigned long flags;
- if (!drm_fbdev_use_shadow_fb(helper)) + if (!drm_fbdev_use_deferred_io(helper)) return;
spin_lock_irqsave(&helper->damage_lock, flags); @@ -2119,8 +2132,16 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) struct drm_fb_helper *fb_helper = info->par;
if (drm_fbdev_use_shadow_fb(fb_helper)) + /* + * Drivers with shadow buffer use fbdev's implementation of + * deferred I/O. + */ return fb_deferred_io_mmap(info, vma); else if (fb_helper->dev->driver->gem_prime_mmap) + /* + * Either directly mmap'ed or with deferred I/O; drivers + * without shadow buffer handle mmap themselves. + */ return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma); else return -ENODEV; @@ -2131,7 +2152,9 @@ static bool drm_fbdev_use_iomem(struct fb_info *info) struct drm_fb_helper *fb_helper = info->par; struct drm_client_buffer *buffer = fb_helper->buffer;
- return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem; + if (drm_fbdev_use_shadow_fb(fb_helper)) + return false; + return buffer->map.is_iomem; }
static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count, @@ -2396,9 +2419,6 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, if (!fbi->screen_buffer) return -ENOMEM; fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST; - - fbi->fbdefio = &drm_fbdev_defio; - fb_deferred_io_init(fbi); } else { /* buffer is mapped for HW framebuffer */ ret = drm_client_buffer_vmap(fb_helper->buffer, &map); @@ -2424,6 +2444,11 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, #endif }
+ if (drm_fbdev_use_deferred_io(fb_helper)) { + fbi->fbdefio = &drm_fbdev_defio; + fb_deferred_io_init(fbi); + } + return 0; }