[PATCH] drm/amdgpu: Fix interrupt handling on ih_soft ring

[Mukul Joshi]

There are no backing hardware registers for ih_soft ring.
As a result, don't try to access hardware registers for read
and write pointers when processing interrupts on the IH soft
ring.

Signed-off-by: Mukul Joshi <mukul.jo...@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/vega20_ih.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/vega20_ih.c 
b/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
index 3b4eb8285943..2022ffbb8dba 100644
--- a/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
@@ -385,9 +385,11 @@ static u32 vega20_ih_get_wptr(struct amdgpu_device *adev,
        u32 wptr, tmp;
        struct amdgpu_ih_regs *ih_regs;
 
-       if (ih == &adev->irq.ih) {
+       if (ih == &adev->irq.ih || ih == &adev->irq.ih_soft) {
                /* Only ring0 supports writeback. On other rings fall back
                 * to register-based code with overflow checking below.
+                * ih_soft ring doesn't have any backing hardware registers,
+                * update wptr and return.
                 */
                wptr = le32_to_cpu(*ih->wptr_cpu);
 
@@ -461,6 +463,9 @@ static void vega20_ih_set_rptr(struct amdgpu_device *adev,
 {
        struct amdgpu_ih_regs *ih_regs;
 
+       if (ih == &adev->irq.ih_soft)
+               return;
+
        if (ih->use_doorbell) {
                /* XXX check if swapping is necessary on BE */
                *ih->rptr_cpu = ih->rptr;
-- 
2.35.1