Re: [PATCH 1/1] drm/radeon: check return value of radeon_ring_lock

From: Christian KÃnig
Date: Mon Apr 24 2017 - 03:47:52 EST


Am 23.04.2017 um 15:36 schrieb Pan Bian:
From: Pan Bian <bianpan2016@xxxxxxx>

Function radeon_ring_lock() returns an errno on failure, and its return
value should be validated. However, in functions r420_cp_errata_init()
and r420_cp_errata_fini(), its return value is not checked. This patch
adds the checks.

Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
---
drivers/gpu/drm/radeon/r420.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r420.c b/drivers/gpu/drm/radeon/r420.c
index 2828605..a8c2b37 100644
--- a/drivers/gpu/drm/radeon/r420.c
+++ b/drivers/gpu/drm/radeon/r420.c
@@ -215,7 +215,8 @@ static void r420_cp_errata_init(struct radeon_device *rdev)
* of the CP init, apparently.
*/
radeon_scratch_get(rdev, &rdev->config.r300.resync_scratch);
- radeon_ring_lock(rdev, ring, 8);
+ if (radeon_ring_lock(rdev, ring, 8))
+ return;

Nice that somebody wants to clean that up, but just returning here is not a good idea.

Additional to that radeon_ring_lock() can only fail if we try to allocate to many dw (impossible with only 8) or the hardware is crashed and then it doesn't matter anyway.

I suggest to just add a WARN_ON() here.

Regards,
Christian.

radeon_ring_write(ring, PACKET0(R300_CP_RESYNC_ADDR, 1));
radeon_ring_write(ring, rdev->config.r300.resync_scratch);
radeon_ring_write(ring, 0xDEADBEEF);
@@ -229,7 +230,8 @@ static void r420_cp_errata_fini(struct radeon_device *rdev)
/* Catch the RESYNC we dispatched all the way back,
* at the very beginning of the CP init.
*/
- radeon_ring_lock(rdev, ring, 8);
+ if (radeon_ring_lock(rdev, ring, 8))
+ return;
radeon_ring_write(ring, PACKET0(R300_RB3D_DSTCACHE_CTLSTAT, 0));
radeon_ring_write(ring, R300_RB3D_DC_FINISH);
radeon_ring_unlock_commit(rdev, ring, false);