[PATCH 3/5] drm/amdgpu/vce4: workaround multi vce engine encoding hang issue

[Yu, Xiangliang]

> Am 09.04.2017 um 14:31 schrieb Xiangliang Yu:
> > For SRIOV, multi vce engine will hang when encoding. Add VMHUB flush
> > to workaround it, will continue to find the root cause later.
> 
> NAK, that won't work and can cause hangs as well.
> 
> The hang you experience could be a known issue with old libdrm, do you
> have updated to the latest version?

Ok, I'll try it later.

> 
> >
> > Signed-off-by: Xiangliang Yu <Xiangliang.Yu at amd.com>
> > Signed-off-by: Frank Min <Frank.Min at amd.com>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/vce_v4_0.c | 11 +++++++++++
> >   1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/vce_v4_0.c
> > b/drivers/gpu/drm/amd/amdgpu/vce_v4_0.c
> > index d3448d0..b4e36f3 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/vce_v4_0.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/vce_v4_0.c
> > @@ -31,6 +31,7 @@
> >   #include "soc15d.h"
> >   #include "soc15_common.h"
> >   #include "mmsch_v1_0.h"
> > +#include "gmc_v9_0.h"
> >
> >   #include "vega10/soc15ip.h"
> >   #include "vega10/VCE/vce_4_0_offset.h"
> > @@ -971,6 +972,7 @@ static void vce_v4_0_emit_vm_flush(struct
> amdgpu_ring *ring,
> >   	uint32_t req = ring->adev->gart.gart_funcs-
> >get_invalidate_req(vm_id);
> >   	unsigned eng = ring->idx;
> >   	unsigned i;
> > +	struct amdgpu_device *adev = ring->adev;
> >
> >   	pd_addr = pd_addr | 0x1; /* valid bit */
> >   	/* now only use physical base address of PDE and valid */ @@ -979,6
> > +981,15 @@ static void vce_v4_0_emit_vm_flush(struct amdgpu_ring
> *ring,
> >   	for (i = 0; i < AMDGPU_MAX_VMHUBS; ++i) {
> >   		struct amdgpu_vmhub *hub = &ring->adev->vmhub[i];
> >
> > +		/* Workaround multi vce engine encoding hang issue */
> > +		if (i && amdgpu_sriov_vf(adev)) {
> > +			WREG32_NO_KIQ(hub->ctx0_ptb_addr_lo32 +
> vm_id * 2,
> > +				      lower_32_bits(pd_addr));
> > +			WREG32_NO_KIQ(hub->ctx0_ptb_addr_hi32 +
> vm_id * 2,
> > +				      upper_32_bits(pd_addr));
> > +			gmc_v9_0_flush_vmhub(adev, hub, eng, vm_id);
> > +		}
> > +
> >   		amdgpu_ring_write(ring, VCE_CMD_REG_WRITE);
> >   		amdgpu_ring_write(ring,
> >   			(hub->ctx0_ptb_addr_hi32 + vm_id * 2) << 2);
>