Fix OOM scenario by doing multiple notifications to the OOM handler through
a busy wait logic.
Changes from commit 5a838e5d5825 ("drm/qxl: simplify qxl_fence_wait") would
result in a '[TTM] Buffer eviction failed' exception whenever it reached a
timeout.

Fixes: 5a838e5d5825 ("drm/qxl: simplify qxl_fence_wait")
Link: 
https://lore.kernel.org/regressions/fb0fda6a-3750-4e1b-893f-97a3e402b...@leemhuis.info
Reported-by: Timo Lindfors <timo.lindf...@iki.fi>
Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054514
Signed-off-by: Alex Constantino <dreaming.about.electric.sh...@gmail.com>
---
 drivers/gpu/drm/qxl/qxl_release.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/qxl/qxl_release.c 
b/drivers/gpu/drm/qxl/qxl_release.c
index 368d26da0d6a..51c22e7f9647 100644
--- a/drivers/gpu/drm/qxl/qxl_release.c
+++ b/drivers/gpu/drm/qxl/qxl_release.c
@@ -20,8 +20,6 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include <linux/delay.h>
-
 #include <trace/events/dma_fence.h>
 
 #include "qxl_drv.h"
@@ -59,14 +57,24 @@ static long qxl_fence_wait(struct dma_fence *fence, bool 
intr,
 {
        struct qxl_device *qdev;
        unsigned long cur, end = jiffies + timeout;
+       signed long iterations = 1;
+       signed long timeout_fraction = timeout;
 
        qdev = container_of(fence->lock, struct qxl_device, release_lock);
 
-       if (!wait_event_timeout(qdev->release_event,
+       // using HZ as a factor since it is used in ttm_bo_wait_ctx too
+       if (timeout_fraction > HZ) {
+               iterations = timeout_fraction / HZ;
+               timeout_fraction = HZ;
+       }
+       for (int i = 0; i < iterations; i++) {
+               if (wait_event_timeout(
+                               qdev->release_event,
                                (dma_fence_is_signaled(fence) ||
-                                (qxl_io_notify_oom(qdev), 0)),
-                               timeout))
-               return 0;
+                                       (qxl_io_notify_oom(qdev), 0)),
+                               timeout_fraction))
+                       break;
+       }
 
        cur = jiffies;
        if (time_after(cur, end))
-- 
2.39.2


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