drm/qxl: fix lockdep issue in qxl_alloc_release_reserved

Call qxl_bo_unpin (which does a reservation) without holding the
release_mutex lock.  Fixes lockdep (correctly) warning on a possible
deadlock.

Fixes: 65ffea3c6e ("drm/qxl: unpin release objects")
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20210217123213.2199186-5-kraxel@redhat.com
This commit is contained in:
Gerd Hoffmann 2021-02-17 13:32:06 +01:00
parent 4fff19ae42
commit 19089b760e

View File

@ -283,7 +283,7 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
int type, struct qxl_release **release,
struct qxl_bo **rbo)
{
struct qxl_bo *bo;
struct qxl_bo *bo, *free_bo = NULL;
int idr_ret;
int ret = 0;
union qxl_release_info *info;
@ -315,8 +315,7 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
mutex_lock(&qdev->release_mutex);
if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) {
qxl_bo_unpin(qdev->current_release_bo[cur_idx]);
qxl_bo_unref(&qdev->current_release_bo[cur_idx]);
free_bo = qdev->current_release_bo[cur_idx];
qdev->current_release_bo_offset[cur_idx] = 0;
qdev->current_release_bo[cur_idx] = NULL;
}
@ -324,6 +323,10 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
ret = qxl_release_bo_alloc(qdev, &qdev->current_release_bo[cur_idx], priority);
if (ret) {
mutex_unlock(&qdev->release_mutex);
if (free_bo) {
qxl_bo_unpin(free_bo);
qxl_bo_unref(&free_bo);
}
qxl_release_free(qdev, *release);
return ret;
}
@ -339,6 +342,10 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
*rbo = bo;
mutex_unlock(&qdev->release_mutex);
if (free_bo) {
qxl_bo_unpin(free_bo);
qxl_bo_unref(&free_bo);
}
ret = qxl_release_list_add(*release, bo);
qxl_bo_unref(&bo);