[PATCH v2] drm/i915/gvt: Handle GEN9_WM_CHICKEN3 with F_CMD_ACCESS for BXT.

[Zhenyu Wang]

On 2018.08.17 09:35:47 +0800, Colin Xu wrote:
> On 8/17/18 8:44 AM, Colin Xu wrote:
> > 
> > On 8/17/18 8:02 AM, Zhao Yan wrote:
> > > GEN9_WM_CHICKEN3 is contained in render engine ctx, so it's
> > > reasonable to
> > > have F_CMD_ACCESS flag.
> > > one concern is that GEN9_WM_CHICKEN3 should be command accessible in skl
> > > also, although in skl platform there's no LRI to program it yet. so
> > > do we
> > > need to limit platform as D_BXT here?
> > 
> > It seems GEN9_WM_CHICKEN3 is only applied to BXT now in i915. I'll
> > double check
> > the behaviour SKL and KBL platform and update later.
> Confirmed that no such issue happens on SKL or KBL.

Even no workaround applied with it, if from HW aspect it should be F_CMD_ACCESS,
then I think we need to take that too.

> > > On Thu, Aug 16, 2018 at 03:58:25PM +0800, Colin Xu wrote:
> > > > Recent patch introduce strict check on scanning cmd:
> > > > Commit 8d458ea0ec33 ("drm/i915/gvt: return error on cmd access")
> > > > 
> > > > Before 8d458ea0ec33, if cmd_reg_handler() checks that a cmd
> > > > access a mmio
> > > > that not marked as F_CMD_ACCESS, it simply returns 0 and log an error.
> > > > Now it will return -EBADRQC which will cause the workload fail
> > > > to submit.
> > > > 
> > > > On BXT, i915 applies WaClearHIZ_WM_CHICKEN3 which will program
> > > > GEN9_WM_CHICKEN3 by LRI when init wa ctx. If it has no
> > > > F_CMD_ACCESS flag,
> > > > vgpu will fail to start. Also add F_MODE_MASK since it's mode mask reg.
> > > > 
> > > > v2: Refresh commit message to elaborate issue symptom in detail.
> > > > 
> > > > Signed-off-by: Colin Xu <colin.xu at intel.com>
> > > > ---
> > > >   drivers/gpu/drm/i915/gvt/handlers.c | 2 ++
> > > >   1 file changed, 2 insertions(+)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/gvt/handlers.c
> > > > b/drivers/gpu/drm/i915/gvt/handlers.c
> > > > index cf2a4020949d..e32a69fabda3 100644
> > > > --- a/drivers/gpu/drm/i915/gvt/handlers.c
> > > > +++ b/drivers/gpu/drm/i915/gvt/handlers.c
> > > > @@ -3205,6 +3205,8 @@ static int init_bxt_mmio_info(struct
> > > > intel_gvt *gvt)
> > > >       MMIO_D(GEN8_L3SQCREG1, D_BXT);
> > > >         MMIO_DFH(GEN9_CTX_PREEMPT_REG, D_BXT, F_CMD_ACCESS,
> > > > NULL, NULL);
> > > > +    MMIO_DFH(GEN9_WM_CHICKEN3, D_BXT,
> > > > +         F_MODE_MASK | F_CMD_ACCESS, NULL, NULL);
> > > >         return 0;
> > > >   }
> > > > -- 
> > > > 2.18.0
> > > > 
> > > > _______________________________________________
> > > > intel-gvt-dev mailing list
> > > > intel-gvt-dev at lists.freedesktop.org
> > > > https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
> > > _______________________________________________
> > > intel-gvt-dev mailing list
> > > intel-gvt-dev at lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
> > 
> -- 
> Best Regards,
> Colin Xu
> 
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev

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