[Intel-gfx] [PATCH 2/2] drm/i915: Test all fw tables during mock selftests

[Tvrtko Ursulin]

On 08/12/2016 22:29, Chris Wilson wrote:
> On Thu, Dec 08, 2016 at 04:52:24PM +0000, Tvrtko Ursulin wrote:
>> Idea for another late test:
>>
>> for (offset = 0; offset < 0x40000; offset++) {
>> 	fw_domain = intel_uncore_forcewake_for_reg(dev_priv, { .reg =
>> offset }, FW_REG_READ | FW_REG_WRITE);
>> 	if (WARN_ON(fw_domain & ~dev_priv->uncore.fw_domains))
>> 		return -EINVAL;
>> }
>>
>> And then we could convert the existing related WARNs in the live
>> code base to GEM_WARN_ONs.
>
> I liked it enough to type something up... However, isn't the argument
> for skipping some fw_domains that the associated register banks are
> invalid/absent on those platforms? i.e. we can't simply walk
> 	for (offset = 0; NEEDS_FORCE_WAKE(offset); offset++)
> and expect every offset to correspond to a register (and so need a
> covering fw_domain)?

I thought it won't be a problem because it would return 0 in those 
cases. So only those offsets that need a forcewake in a platform can 
trigger the fail.

Oh I see. We would need another layer before the condition checking, like:

fw_domains = intel_uncore_forcewake_for_reg(...)
if ((fw_domains & FORCEWAKE_MEDIA) && !HAS_ENGINE(VCS))
	fw_domains &= ~FORCEWAKE_MEDIA;
...
WARN_ON(fw_domains & ~...);

Would that work?

Regards,

Tvrtko