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| author | Thomas Zimmermann <tzimmermann@suse.de> | 2022-04-29 12:08:30 +0200 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2022-05-03 16:04:21 +0200 |
| commit | 5905585103276b7c14bb9a7de4b575216cb6dac4 (patch) | |
| tree | b440972605773f8144366c0d96394ce32136f1d2 /drivers/gpu/drm/drm_fb_helper.c | |
| parent | 594e9c04b5864b4b8b151ef4ba9521c59e0f5c54 (diff) | |
| download | linux-5905585103276b7c14bb9a7de4b575216cb6dac4.tar.gz linux-5905585103276b7c14bb9a7de4b575216cb6dac4.tar.bz2 linux-5905585103276b7c14bb9a7de4b575216cb6dac4.zip | |
fbdev: Put mmap for deferred I/O into drivers
The fbdev mmap function fb_mmap() unconditionally overrides the
driver's implementation if deferred I/O has been activated. This
makes it hard to implement mmap with anything but a vmalloc()'ed
software buffer. That is specifically a problem for DRM, where
video memory is maintained by a memory manager.
Leave the mmap handling to drivers and expect them to call the
helper for deferred I/O by thmeselves.
v4:
* unlock mm_lock in fb_mmap() error path (Dan)
v3:
* fix warning if fb_mmap is missing (kernel test robot)
v2:
* print a helpful error message if the defio setup is
incorrect (Javier)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-2-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu/drm/drm_fb_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_fb_helper.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index d265a73313c9..d06ce0e92d66 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2118,7 +2118,9 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) { struct drm_fb_helper *fb_helper = info->par; - if (fb_helper->dev->driver->gem_prime_mmap) + if (drm_fbdev_use_shadow_fb(fb_helper)) + return fb_deferred_io_mmap(info, vma); + else if (fb_helper->dev->driver->gem_prime_mmap) return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma); else return -ENODEV; |