[AMD Official Use Only - General]
+ /* release the gfx mutex */
+ tmp = REG_SET_FIELD(tmp, CP_GFX_INDEX_MUTEX, REQUEST, 0);
+ WREG32_SOC15(GC, 0, regCP_GFX_INDEX_MUTEX, tmp);
Shall we add a check by reading back CP_GFX_INDEX_MUTEX to ensure the release is done correctly?
Regards,
Hawking
-----Original Message-----
From: Xiao, Jack <Jack.Xiao@xxxxxxx>
Sent: Tuesday, December 19, 2023 17:24
To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Zhang, Hawking <Hawking.Zhang@xxxxxxx>
Cc: Xiao, Jack <Jack.Xiao@xxxxxxx>
Subject: [PATCH] drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET
It's required to take the gfx mutex before access to CP_VMID_RESET, for there is a race condition with CP firmware to write the register.
Signed-off-by: Jack Xiao <Jack.Xiao@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
index bdcf96df69e6..ae3370d34d11 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
@@ -4518,6 +4518,22 @@ static int gfx_v11_0_soft_reset(void *handle)
}
}
+ /* Try to require the gfx mutex before access to CP_VMID_RESET */
+ for (i = 0; i < adev->usec_timeout; i++) {
+ /* Request with MeId=2, PipeId=0 */
+ tmp = REG_SET_FIELD(0, CP_GFX_INDEX_MUTEX, REQUEST, 1);
+ tmp = REG_SET_FIELD(tmp, CP_GFX_INDEX_MUTEX, CLIENTID, 4);
+ WREG32_SOC15(GC, 0, regCP_GFX_INDEX_MUTEX, tmp);
+ if (RREG32_SOC15(GC, 0, regCP_GFX_INDEX_MUTEX) == tmp)
+ break;
+ udelay(1);
+ }
+
+ if (i >= adev->usec_timeout) {
+ printk("Failed to require the gfx mutex during soft reset\n");
+ return -EINVAL;
+ }
+
WREG32_SOC15(GC, 0, regCP_VMID_RESET, 0xfffffffe);
// Read CP_VMID_RESET register three times.
@@ -4526,6 +4542,10 @@ static int gfx_v11_0_soft_reset(void *handle)
RREG32_SOC15(GC, 0, regCP_VMID_RESET);
RREG32_SOC15(GC, 0, regCP_VMID_RESET);
+ /* release the gfx mutex */
+ tmp = REG_SET_FIELD(tmp, CP_GFX_INDEX_MUTEX, REQUEST, 0);
+ WREG32_SOC15(GC, 0, regCP_GFX_INDEX_MUTEX, tmp);
+
for (i = 0; i < adev->usec_timeout; i++) {
if (!RREG32_SOC15(GC, 0, regCP_HQD_ACTIVE) &&
!RREG32_SOC15(GC, 0, regCP_GFX_HQD_ACTIVE))
--
2.41.0
