From e998d3c8cba93ab4075d6bcc56b1d4451d85efe5 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Wed, 17 Feb 2021 13:32:06 +0100 Subject: [PATCH] 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: e8dd3506dcf3 ("drm/qxl: unpin release objects") Signed-off-by: Gerd Hoffmann Acked-by: Thomas Zimmermann Link: http://patchwork.freedesktop.org/patch/msgid/20210217123213.2199186-5-kraxel@redhat.com (cherry picked from commit 19089b760e56c97458c272e90e43da761b05cf12) Signed-off-by: Maarten Lankhorst --- 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 93b5f7ab055d..b372455e2729 100644 --- a/drivers/gpu/drm/qxl/qxl_release.c +++ b/drivers/gpu/drm/qxl/qxl_release.c @@ -321,7 +321,7 @@ 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; @@ -347,8 +347,7 @@ 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; } @@ -356,6 +355,10 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size, ret = qxl_release_bo_alloc(qdev, &qdev->current_release_bo[cur_idx]); 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; } @@ -371,6 +374,10 @@ 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);