The bspec says "These are basic methods that can be used for single and 
multi-pipe modes. For optimal power usage, the display driver can choose to use 
more advanced allocation techniques as desired."
So we leave it up to the driver to optimize as it sees fit.

-----Original Message-----
From: Rodrigo Vivi [mailto:rodrigo.v...@gmail.com] 
Sent: Thursday, June 16, 2016 4:20 PM
To: Sripada, Radhakrishna
Cc: intel-gfx; drm-intel-fi...@lists.freedesktop.org; Runyan, Arthur J
Subject: Re: [Intel-gfx] [PATCH] drm/i915/skl: Increase cursor ddb blocks in 
multi-pipe config

I believe we should use whatever BSpec recommends.

If that is not the best behavior and block things out than the spec needs to be 
updated or a workaround documented there.

Art? thoughts?

On Mon, Jun 13, 2016 at 3:03 PM, Radhakrishna Sripada 
<radhakrishna.srip...@intel.com> wrote:
> The bspec suggests giving cursor planes a fixed allocation of 8 blocks 
> when running in a multi-CRTC configuration.  However we have found 
> that this small allocation can only accommodate level
> 0 watermarks on many platforms, which in turn prevents the system from 
> entering deeper sleep states.  Let's use a slightly higher allocation 
> of 16 blocks for the cursor to increase our chances of enabling lower 
> power states.
>
> Signed-off-by: Radhakrishna Sripada <radhakrishna.srip...@intel.com>
> Signed-off-by: Matt Roper <matthew.d.ro...@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c 
> b/drivers/gpu/drm/i915/intel_pm.c index 658a756..a949dac 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -2933,7 +2933,8 @@ static unsigned int skl_cursor_allocation(int 
> num_active)
>         if (num_active == 1)
>                 return 32;
>
> -       return 8;
> +       /* higher than bspec recommendation (8) */
> +       return 16;
>  }
>
>  static void skl_ddb_entry_init_from_hw(struct skl_ddb_entry *entry, 
> u32 reg)
> --
> 1.9.1
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx



--
Rodrigo Vivi
Blog: http://blog.vivi.eng.br
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