drm/amdgpu: clear RB_OVERFLOW bit when enabling interrupts

Why:
Setting IH_RB_WPTR register to 0 will not clear the RB_OVERFLOW bit
if RB_ENABLE is not set.

How to fix:
Set WPTR_OVERFLOW_CLEAR bit after RB_ENABLE bit is set.
The RB_ENABLE bit is required to be set, together with
WPTR_OVERFLOW_ENABLE bit so that setting WPTR_OVERFLOW_CLEAR bit
would clear the RB_OVERFLOW.

Signed-off-by: Danijel Slivka <danijel.slivka@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c b/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
index 3cb64c8f71758941137c23f621c9e42f216ccc33..18a761d6ef33061a6c3648408474b2816cef77a5 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
@@ -135,6 +135,34 @@ static int ih_v6_0_toggle_ring_interrupts(struct amdgpu_device *adev,
 
        tmp = RREG32(ih_regs->ih_rb_cntl);
        tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, RB_ENABLE, (enable ? 1 : 0));
+
+       if (enable) {
+               /* Unset the CLEAR_OVERFLOW bit to make sure the next step
+                * is switching the bit from 0 to 1
+                */
+               tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 0);
+               if (amdgpu_sriov_vf(adev) && amdgpu_sriov_reg_indirect_ih(adev)) {
+                       if (psp_reg_program(&adev->psp, ih_regs->psp_reg_id, tmp))
+                               return -ETIMEDOUT;
+               } else {
+                       WREG32_NO_KIQ(ih_regs->ih_rb_cntl, tmp);
+               }
+
+               /* Clear RB_OVERFLOW bit */
+               tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 1);
+               if (amdgpu_sriov_vf(adev) && amdgpu_sriov_reg_indirect_ih(adev)) {
+                       if (psp_reg_program(&adev->psp, ih_regs->psp_reg_id, tmp))
+                               return -ETIMEDOUT;
+               } else {
+                       WREG32_NO_KIQ(ih_regs->ih_rb_cntl, tmp);
+               }
+
+               /* Unset the CLEAR_OVERFLOW bit immediately so new overflows
+                * can be detected.
+                */
+               tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 0);
+       }
+
        /* enable_intr field is only valid in ring0 */
        if (ih == &adev->irq.ih)
                tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, ENABLE_INTR, (enable ? 1 : 0));