From a22bdc13c786cae153fb05ebfff23ddfbb4c965b Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 16 Mar 2022 11:41:48 +0300
Subject: drm/amdgpu: fix off by one in amdgpu_gfx_kiq_acquire()
Git-commit: 1647b54ed55d4d48c7199d439f8834626576cbe9
Patch-mainline: v5.18-rc2
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
This post-op should be a pre-op so that we do not pass -1 as the bit
number to test_bit(). The current code will loop downwards from 63 to
-1. After changing to a pre-op, it loops from 63 to 0.
Fixes: 71c37505e7ea ("drm/amdgpu/gfx: move more common KIQ code to amdgpu_gfx.c")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index 8fe939976224..28a736c507bb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -266,7 +266,7 @@ static int amdgpu_gfx_kiq_acquire(struct amdgpu_device *adev,
* adev->gfx.mec.num_pipe_per_mec
* adev->gfx.mec.num_queue_per_pipe;
- while (queue_bit-- >= 0) {
+ while (--queue_bit >= 0) {
if (test_bit(queue_bit, adev->gfx.mec.queue_bitmap))
continue;
--
2.38.1