[Intel-gfx] [PATCH] drm/i915: vlv: reserve the GT power context only once during driver init

[Ville Syrjälä]

On Mon, Mar 31, 2014 at 03:10:44PM +0300, Imre Deak wrote:
> Atm we reserve/allocate and free the power context during GT power
> enable/disable time. There is no need to do this, we can reserve/allocate
> the buffer once during driver loading and free it during driver cleanup.
> The re-reservation can also fail in case the driver previously manages to
> allocate something on the given fixed address.
> 
> The buffer isn't exepected to move even if allocated by the BIOS, for
> safety add an assert to check this assumption.
> 
> This also fixed a bug for Ville, where re-reserving the context failed
> during a GPU reset (I assume because something else got allocated on its
> fixed address).

I'm assuming it was the already existing pctx allocation that caused the
warning. We just call intel_enable_gt_powersave() again during GPU reset
w/o having called intel_disable_gt_powersave() anywhere. So no danger of
clobbering the pctx AFAICS, but getting a WARN on every GPU reset is
rather annoying.

> 
> Tested-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>

The patch looks good to me.

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

<snip>

-- 
Ville Syrjälä
Intel OTC