From: Jerome Glisse jglisse@redhat.com

This patch print a warning message when trying to reserve same buffer twice in same cs ioctl (because the buffer is known by userspace under 2 different handle). It does not try to fix the issue like :

https://patchwork.kernel.org/patch/1812991/

Just to make this case easier to debug.

v2: Make message a debug one not an error

Cc: stable@vger.kernel.org Signed-off-by: Jerome Glisse jglisse@redhat.com --- drivers/gpu/drm/radeon/radeon_object.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index d3aface..624ea8c 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -355,6 +355,18 @@ int radeon_bo_list_validate(struct list_head *head)

r = ttm_eu_reserve_buffers(head); if (unlikely(r != 0)) { + if (r == -EDEADLK) { + /* this is not a GPU lockup, ttm_eu_reserve_buffers + * can not trigger detection of GPU lockup. This is + * a dead lock trying to reserve the same buffer again + * probably because the buffer is know as 2 different + * handle by userspace. Print a warning message so + * that we know what's going on. + */ + DRM_DEBUG("Dead lock reserving buffer (one buffer is know by userspace under 2 different handle)\n"); + /* Do not return -EDEADLK to avoid useless GPU reset */ + return -EINVAL; + } return r; } list_for_each_entry(lobj, head, tv.head) {