drm/ast: do not attempt to acquire a reservation while in an interrupt handler

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@canonical.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
index fbc0823cfa18b9dbd35588d07d3c9322c58bc18d..7b33e14e44aa17a8026d4c1c33b8e2dbc529f93f 100644 (file)
--- a/drivers/gpu/drm/ast/ast_fb.c
+++ b/drivers/gpu/drm/ast/ast_fb.c
@@ -51,7 +51,7 @@ static void ast_dirty_update(struct ast_fbdev *afbdev,
        struct ast_bo *bo;
        int src_offset, dst_offset;
        int bpp = (afbdev->afb.base.bits_per_pixel + 7)/8;
-       int ret;
+       int ret = -EBUSY;
        bool unmap = false;
        bool store_for_later = false;
        int x2, y2;
@@ -65,7 +65,8 @@ static void ast_dirty_update(struct ast_fbdev *afbdev,
         * then the BO is being moved and we should
         * store up the damage until later.
         */
-       ret = ast_bo_reserve(bo, true);
+       if (!in_interrupt())
+               ret = ast_bo_reserve(bo, true);
        if (ret) {
                if (ret != -EBUSY)
                        return;