drm/nouveau: fallback to sw fbcon if we can't get mutex immediately

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index bc30dbe..0fce4eb 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -61,8 +61,8 @@ nouveau_fbcon_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
                return;
 
        ret = -ENODEV;
-       if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {
-               mutex_lock(&dev_priv->channel->mutex);
+       if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED) &&
+           mutex_trylock(&dev_priv->channel->mutex)) {
                if (dev_priv->card_type < NV_50)
                        ret = nv04_fbcon_fillrect(info, rect);
                else
@@ -91,8 +91,8 @@ nouveau_fbcon_copyarea(struct fb_info *info, const struct fb_copyarea *image)
                return;
 
        ret = -ENODEV;
-       if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {
-               mutex_lock(&dev_priv->channel->mutex);
+       if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED) &&
+           mutex_trylock(&dev_priv->channel->mutex)) {
                if (dev_priv->card_type < NV_50)
                        ret = nv04_fbcon_copyarea(info, image);
                else
@@ -121,8 +121,8 @@ nouveau_fbcon_imageblit(struct fb_info *info, const struct fb_image *image)
                return;
 
        ret = -ENODEV;
-       if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {
-               mutex_lock(&dev_priv->channel->mutex);
+       if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED) &&
+           mutex_trylock(&dev_priv->channel->mutex)) {
                if (dev_priv->card_type < NV_50)
                        ret = nv04_fbcon_imageblit(info, image);
                else
@@ -153,7 +153,9 @@ nouveau_fbcon_sync(struct fb_info *info)
            info->flags & FBINFO_HWACCEL_DISABLED)
                return 0;
 
-       mutex_lock(&chan->mutex);
+       if (!mutex_trylock(&chan->mutex))
+               return 0;
+
        ret = RING_SPACE(chan, 4);
        if (ret) {
                mutex_unlock(&chan->mutex);