| Message ID | 20210217123213.2199186-5-kraxel@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/qxl: a collection of fixes | expand |
Am 17.02.21 um 13:32 schrieb Gerd Hoffmann: > Call qxl_bo_unpin (which does a reservation) without holding the > release_mutex lock. Fixes lockdep (correctly) warning on a possible > deadlock. > > Fixes: 65ffea3c6e73 ("drm/qxl: unpin release objects") > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> > --- > drivers/gpu/drm/qxl/qxl_release.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c > index 716d706ca7f0..f5845c96d414 100644 > --- a/drivers/gpu/drm/qxl/qxl_release.c > +++ b/drivers/gpu/drm/qxl/qxl_release.c > @@ -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); >
diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c index 716d706ca7f0..f5845c96d414 100644 --- a/drivers/gpu/drm/qxl/qxl_release.c +++ b/drivers/gpu/drm/qxl/qxl_release.c @@ -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);
Call qxl_bo_unpin (which does a reservation) without holding the release_mutex lock. Fixes lockdep (correctly) warning on a possible deadlock. Fixes: 65ffea3c6e73 ("drm/qxl: unpin release objects") Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- drivers/gpu/drm/qxl/qxl_release.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)