[Intel-gfx] [PATCH 1/2] intel: Add support for overriding the PCI ID via an environment variable

[Kenneth Graunke]

On 02/21/2012 01:11 PM, Chris Wilson wrote:
> On Tue, 21 Feb 2012 12:59:37 -0800, Kenneth Graunke<kenneth at whitecape.org>  wrote:
>> @@ -1828,6 +1829,9 @@ drm_intel_gem_bo_mrb_exec2(drm_intel_bo *bo, int used,
>>   	execbuf.rsvd1 = 0;
>>   	execbuf.rsvd2 = 0;
>>
>> +	if (getenv("INTEL_DEVID_OVERRIDE"))
>> +		goto skip_execution;
>
> I'm not thrilled about calling getenv() for every execbuffer.

Good point.  I'll have to fix that.

> And what about the original execbuffer path?
> -Chris

Does anybody care?  I'm not even sure how I'd test it.

A little bit of background: this is a stepping stone on the way to 
simulator support.

When INTEL_DEVID_OVERRIDE is set, Mesa will generate code/batches for 
that system, rather than the current machine.  It also implicitly sets 
INTEL_NO_HW=1, which makes it avoid calling execbuf2.  This at least 
allows INTEL_DEBUG=vs,wm,bat style dumps, which is handy.

However, our .aub trace file support is in libdrm, so I need Mesa to 
execbuf, or I don't get aub file dumps.  But I don't want libdrm to 
-actually- exec it.