Re: [PATCH v4 10/12] drm/i915: Program PFI credits for VLV

Daniel Vetter
2015-03-10T10:26:56Z

On Tue, Mar 10, 2015 at 03:35:19PM +0530, Purushothaman, Vijay A wrote:
> On 3/6/2015 12:49 AM, ville.syrjala@linux.intel.com wrote:
> >From: Vidya Srinivas <vidya.srinivas@intel.com>
> >
> >PFI credit programming is required when CD clock (related to data flow from
> >display pipeline to end display) is greater than CZ clock (related to data
> >flow from memory to display plane). This programming should be done when all
> >planes are OFF to avoid intermittent hangs while accessing memory even from
> >different Gfx units (not just display).
> >
> >If cdclk/czclk >=1, PFI credits could be set as any number. To get better
> >performance, larger PFI credit can be assigned to PND. Otherwise if
> >cdclk/czclk<1, the default PFI credit of 8 should be set.
> >
> >v2:
> > - Change log to lower log level instead of DRM_ERROR
> > - Change function name to valleyview_program_pfi_credits
> > - Move program PFI credits to modeset_init instead of intel_set_mode
> > - Change magic numbers to logical constants
> >
> >[vsyrjala v3:
> > - only program in response to cdclk update
> > - program the credits also when cdclk<czclk
> > - add CHV bits
> > v4:
> > - Change CHV cdclk<czclk credits to 12 (Vijay)]
> >
> >Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> >Signed-off-by: Gajanan Bhat <gajanan.bhat@intel.com>
> >Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
> >Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >---
>
> Reviewed-by: Vijay Purushothaman <vijay.a.purushothaman@linux.intel.com>

Pulled in the remaining 4 patches from this series, thanks.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch