drm/amdgpu: workaround tonga HW bug in HQD programming sequence

Tonga based asics may experience hangs when an HQD's EOP parameters
are modified.

Workaround this HW issue by avoiding writes to these registers for
tonga asics.

Based on the following ROCm commit:
2a0fb8 - drm/amdgpu: Synchronize KFD HQD load protocol with CP scheduler

From the ROCm git repository:
https://github.com/RadeonOpenCompute/ROCK-Kernel-Driver.git

CC: Jay Cornwall <Jay.Cornwall@amd.com>
Suggested-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index 29ec429a54c56a528f70d5c456fbed6ab40e2b45..69d9bbd4e87868e5666c4277eb209ae691810df6 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -5070,7 +5070,21 @@ int gfx_v8_0_mqd_commit(struct amdgpu_device *adev,
        WREG32_FIELD(CP_PQ_WPTR_POLL_CNTL, EN, 0);
 
        /* program all HQD registers */
-       for (mqd_reg = mmCP_HQD_VMID; mqd_reg <= mmCP_HQD_ERROR; mqd_reg++)
+       for (mqd_reg = mmCP_HQD_VMID; mqd_reg <= mmCP_HQD_EOP_CONTROL; mqd_reg++)
+               WREG32(mqd_reg, mqd_data[mqd_reg - mmCP_MQD_BASE_ADDR]);
+
+       /* Tonga errata: EOP RPTR/WPTR should be left unmodified.
+        * This is safe since EOP RPTR==WPTR for any inactive HQD
+        * on ASICs that do not support context-save.
+        * EOP writes/reads can start anywhere in the ring.
+        */
+       if (adev->asic_type != CHIP_TONGA) {
+               WREG32(mmCP_HQD_EOP_RPTR, mqd->cp_hqd_eop_rptr);
+               WREG32(mmCP_HQD_EOP_WPTR, mqd->cp_hqd_eop_wptr);
+               WREG32(mmCP_HQD_EOP_WPTR_MEM, mqd->cp_hqd_eop_wptr_mem);
+       }
+
+       for (mqd_reg = mmCP_HQD_EOP_EVENTS; mqd_reg <= mmCP_HQD_ERROR; mqd_reg++)
                WREG32(mqd_reg, mqd_data[mqd_reg - mmCP_MQD_BASE_ADDR]);
 
        /* activate the HQD */