drm/nouveau/fbcon: take runpm reference when userspace has an open fd

We need to do this in order to prevent accesses to the device while it's
powered down.  Userspace may have an mmap of the fb, and there's no good
way (that I know of) to prevent it from touching the device otherwise.

This fixes some nasty races between runpm and plymouth on some systems,
which result in the GPU getting very upset and hanging the boot.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Ben Skeggs 2015-10-02 14:03:19 +10:00
parent 953132b56a
commit f231976c2e

View File

@ -178,8 +178,30 @@ nouveau_fbcon_sync(struct fb_info *info)
return 0;
}
static int
nouveau_fbcon_open(struct fb_info *info, int user)
{
struct nouveau_fbdev *fbcon = info->par;
struct nouveau_drm *drm = nouveau_drm(fbcon->dev);
int ret = pm_runtime_get_sync(drm->dev->dev);
if (ret < 0 && ret != -EACCES)
return ret;
return 0;
}
static int
nouveau_fbcon_release(struct fb_info *info, int user)
{
struct nouveau_fbdev *fbcon = info->par;
struct nouveau_drm *drm = nouveau_drm(fbcon->dev);
pm_runtime_put(drm->dev->dev);
return 0;
}
static struct fb_ops nouveau_fbcon_ops = {
.owner = THIS_MODULE,
.fb_open = nouveau_fbcon_open,
.fb_release = nouveau_fbcon_release,
.fb_check_var = drm_fb_helper_check_var,
.fb_set_par = drm_fb_helper_set_par,
.fb_fillrect = nouveau_fbcon_fillrect,
@ -195,6 +217,8 @@ static struct fb_ops nouveau_fbcon_ops = {
static struct fb_ops nouveau_fbcon_sw_ops = {
.owner = THIS_MODULE,
.fb_open = nouveau_fbcon_open,
.fb_release = nouveau_fbcon_release,
.fb_check_var = drm_fb_helper_check_var,
.fb_set_par = drm_fb_helper_set_par,
.fb_fillrect = drm_fb_helper_cfb_fillrect,