[Intel-gfx] [RFC][PATCH] gpu:drm:i915:intel_detect_pch: back to check devfn instead of check class type

[Daniel Vetter]

On Thu, Jul 10, 2014 at 09:08:24PM +0000, Tian, Kevin wrote:
> actually I'm curious whether it's still necessary to __detect__ PCH. Could
> we assume a 1:1 mapping between GPU and PCH, e.g. BDW already hard
> code the knowledge:
> 
>               } else if (IS_BROADWELL(dev)) {
>                       dev_priv->pch_type = PCH_LPT;
>                       dev_priv->pch_id =
>                               INTEL_PCH_LPT_LP_DEVICE_ID_TYPE;
>                       DRM_DEBUG_KMS("This is Broadwell, assuming "
>                                     "LynxPoint LP PCH\n");
> 
> Or if there is real usage on non-fixed mapping (not majority), could it be a 
> better option to have fixed mapping as a fallback instead of leaving as 
> PCH_NONE? Then even when Qemu doesn't provide a special tweaked PCH,
> the majority case just works.

I guess we can do it, at least I haven't seen any strange combinations in
the wild outside of Intel ...
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch