[PATCH] Revert "drm/amdgpu: use polling mem to set SDMA3 wptr for VF"

[Deng, Emily]

Ping....
Hi all,
    Please help review this, the regression introduced by the commit 2ffe31deb27579e2f2c9444e01f4d8abf385d145 is gating the sriov sanity test.

Best Wishes,
Emily Deng


> -----Original Message-----
> From: Emily Deng [mailto:Emily.Deng at amd.com]
> Sent: Friday, March 02, 2018 11:32 AM
> To: amd-gfx at lists.freedesktop.org
> Cc: Deng, Emily <Emily.Deng at amd.com>
> Subject: [PATCH] Revert "drm/amdgpu: use polling mem to set SDMA3 wptr
> for VF"
> 
> This reverts commit 2ffe31deb27579e2f2c9444e01f4d8abf385d145.
> The sdma wptr poll memomy doesn't have the same efficiency as doorbell,
> and it will make sdma hang when running tests.
> 
> Change-Id: I6e334430b309b0c21aa18a08764320c7ff51e353
> Signed-off-by: Emily Deng <Emily.Deng at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h |  1 -
>  drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c   | 27 ++++++++-------------------
>  2 files changed, 8 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index 102dad3..5dcf98b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -186,7 +186,6 @@ struct amdgpu_ring {
>  	uint64_t                eop_gpu_addr;
>  	u32			doorbell_index;
>  	bool			use_doorbell;
> -	bool			use_pollmem;
>  	unsigned		wptr_offs;
>  	unsigned		fence_offs;
>  	uint64_t		current_ctx;
> diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
> b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
> index 521978c..d3fb3ca 100644
> --- a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
> @@ -355,7 +355,7 @@ static uint64_t sdma_v3_0_ring_get_wptr(struct
> amdgpu_ring *ring)
>  	struct amdgpu_device *adev = ring->adev;
>  	u32 wptr;
> 
> -	if (ring->use_doorbell || ring->use_pollmem) {
> +	if (ring->use_doorbell) {
>  		/* XXX check if swapping is necessary on BE */
>  		wptr = ring->adev->wb.wb[ring->wptr_offs] >> 2;
>  	} else {
> @@ -380,13 +380,10 @@ static void sdma_v3_0_ring_set_wptr(struct
> amdgpu_ring *ring)
> 
>  	if (ring->use_doorbell) {
>  		u32 *wb = (u32 *)&adev->wb.wb[ring->wptr_offs];
> +
>  		/* XXX check if swapping is necessary on BE */
>  		WRITE_ONCE(*wb, (lower_32_bits(ring->wptr) << 2));
>  		WDOORBELL32(ring->doorbell_index, lower_32_bits(ring-
> >wptr) << 2);
> -	} else if (ring->use_pollmem) {
> -		u32 *wb = (u32 *)&adev->wb.wb[ring->wptr_offs];
> -
> -		WRITE_ONCE(*wb, (lower_32_bits(ring->wptr) << 2));
>  	} else {
>  		int me = (ring == &ring->adev->sdma.instance[0].ring) ? 0 : 1;
> 
> @@ -719,14 +716,10 @@ static int sdma_v3_0_gfx_resume(struct
> amdgpu_device *adev)
>  		WREG32(mmSDMA0_GFX_RB_WPTR_POLL_ADDR_HI +
> sdma_offsets[i],
>  		       upper_32_bits(wptr_gpu_addr));
>  		wptr_poll_cntl =
> RREG32(mmSDMA0_GFX_RB_WPTR_POLL_CNTL + sdma_offsets[i]);
> -		if (ring->use_pollmem)
> -			wptr_poll_cntl = REG_SET_FIELD(wptr_poll_cntl,
> -
> SDMA0_GFX_RB_WPTR_POLL_CNTL,
> -						       ENABLE, 1);
> +		if (amdgpu_sriov_vf(adev))
> +			wptr_poll_cntl = REG_SET_FIELD(wptr_poll_cntl,
> +SDMA0_GFX_RB_WPTR_POLL_CNTL, F32_POLL_ENABLE, 1);
>  		else
> -			wptr_poll_cntl = REG_SET_FIELD(wptr_poll_cntl,
> -
> SDMA0_GFX_RB_WPTR_POLL_CNTL,
> -						       ENABLE, 0);
> +			wptr_poll_cntl = REG_SET_FIELD(wptr_poll_cntl,
> +SDMA0_GFX_RB_WPTR_POLL_CNTL, F32_POLL_ENABLE, 0);
>  		WREG32(mmSDMA0_GFX_RB_WPTR_POLL_CNTL +
> sdma_offsets[i], wptr_poll_cntl);
> 
>  		/* enable DMA RB */
> @@ -1208,13 +1201,9 @@ static int sdma_v3_0_sw_init(void *handle)
>  	for (i = 0; i < adev->sdma.num_instances; i++) {
>  		ring = &adev->sdma.instance[i].ring;
>  		ring->ring_obj = NULL;
> -		if (!amdgpu_sriov_vf(adev)) {
> -			ring->use_doorbell = true;
> -			ring->doorbell_index = (i == 0) ?
> -				AMDGPU_DOORBELL_sDMA_ENGINE0 :
> AMDGPU_DOORBELL_sDMA_ENGINE1;
> -		} else {
> -			ring->use_pollmem = true;
> -		}
> +		ring->use_doorbell = true;
> +		ring->doorbell_index = (i == 0) ?
> +			AMDGPU_DOORBELL_sDMA_ENGINE0 :
> AMDGPU_DOORBELL_sDMA_ENGINE1;
> 
>  		sprintf(ring->name, "sdma%d", i);
>  		r = amdgpu_ring_init(adev, ring, 1024,
> --
> 2.7.4