Am 04.04.2018 um 07:01 schrieb Emily Deng:
> under SR-IOV sometimes CPU based tlb flush would timeout within
> the given 100ms period, instead let it fail and continue we can
> give it more chance to repeat the tlb flush on the failed VMHUB
>
> this could fix the massive "Timeout waiting for VM flush ACK"
> error during vk_encoder test.
>
> v2:refine the code
>
> Signed-off-by: Monk Liu <Monk.Liu at amd.com>
> Signed-off-by: Emily Deng <Emily.Deng at amd.com>
Acked-by: Christian König <christian.koenig at amd.com>
But that is still a rather ugly workaround, we should probably not
upstream that and wait for the RLC fix instead.
Christian.
> ---
> drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 50 ++++++++++++++++++++---------------
> 1 file changed, 28 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> index 503070f..44602d4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> @@ -328,7 +328,8 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev,
> {
> /* Use register 17 for GART */
> const unsigned eng = 17;
> - unsigned i, j;
> + unsigned retry = 3;
> + unsigned i, j, k;
>
> spin_lock(&adev->gmc.invalidate_lock);
>
> @@ -336,31 +337,36 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev,
> struct amdgpu_vmhub *hub = &adev->vmhub[i];
> u32 tmp = gmc_v9_0_get_invalidate_req(vmid);
>
> - WREG32_NO_KIQ(hub->vm_inv_eng0_req + eng, tmp);
> + for (k = 0; k < retry; ++k) {
>
> - /* Busy wait for ACK.*/
> - for (j = 0; j < 100; j++) {
> - tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_ack + eng);
> - tmp &= 1 << vmid;
> - if (tmp)
> + WREG32_NO_KIQ(hub->vm_inv_eng0_req + eng, tmp);
> +
> + /* Busy wait for ACK.*/
> + for (j = 0; j < 100; j++) {
> + tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_ack + eng);
> + tmp &= 1 << vmid;
> + if (tmp)
> + break;
> + cpu_relax();
> + }
> + if (j < 100)
> break;
> - cpu_relax();
> - }
> - if (j < 100)
> - continue;
> -
> - /* Wait for ACK with a delay.*/
> - for (j = 0; j < adev->usec_timeout; j++) {
> - tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_ack + eng);
> - tmp &= 1 << vmid;
> - if (tmp)
> +
> + /* Wait for ACK with a delay.*/
> + for (j = 0; j < adev->usec_timeout; j++) {
> + tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_ack + eng);
> + tmp &= 1 << vmid;
> + if (tmp)
> + break;
> + udelay(1);
> + }
> + if (j < adev->usec_timeout)
> break;
> - udelay(1);
> + if (k == retry)
> + DRM_ERROR("Timeout waiting for VM flush ACK!\n");
> + else
> + DRM_ERROR("Need one more try to write the VMHUB flush request!");
> }
> - if (j < adev->usec_timeout)
> - continue;
> -
> - DRM_ERROR("Timeout waiting for VM flush ACK!\n");
> }
>
> spin_unlock(&adev->gmc.invalidate_lock);
