[PATCH 8/9] drm/mgag200: do not attempt to acquire a reservation while in an interrupt handler

[Maarten Lankhorst]

Mutexes should not be acquired in interrupt context. While the trylock
fastpath is arguably safe on all implementations, the slowpath
unlock path definitely isn't.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
---
 drivers/gpu/drm/mgag200/mgag200_fb.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_fb.c 
b/drivers/gpu/drm/mgag200/mgag200_fb.c
index 5da824c..964f58c 100644
--- a/drivers/gpu/drm/mgag200/mgag200_fb.c
+++ b/drivers/gpu/drm/mgag200/mgag200_fb.c
@@ -27,7 +27,7 @@ static void mga_dirty_update(struct mga_fbdev *mfbdev,
        struct mgag200_bo *bo;
        int src_offset, dst_offset;
        int bpp = (mfbdev->mfb.base.bits_per_pixel + 7)/8;
-       int ret;
+       int ret = -EBUSY;
        bool unmap = false;
        bool store_for_later = false;
        int x2, y2;
@@ -41,7 +41,8 @@ static void mga_dirty_update(struct mga_fbdev *mfbdev,
         * then the BO is being moved and we should
         * store up the damage until later.
         */
-       ret = mgag200_bo_reserve(bo, true);
+       if (!in_interrupt())
+               ret = mgag200_bo_reserve(bo, true);
        if (ret) {
                if (ret != -EBUSY)
                        return;
-- 
1.8.3.1