[PATCH 4.1 32/46] drm/nouveau/fbcon: take runpm reference when userspace has an open fd

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



4.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Skeggs <bskeggs@xxxxxxxxxx>

commit f231976c2e8964ceaa9250e57d27c35ff03825c2 upstream.

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@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/nouveau/nouveau_fbcon.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -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 = cfb_fillrect,


--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]