Quoting Lucas De Marchi (2018-08-31 17:06:01)
> On Fri, Aug 31, 2018 at 09:16:23AM +0100, Chris Wilson wrote:
> > Quoting Lucas De Marchi (2018-08-29 01:35:28)
> > > +bool intel_is_genx(unsigned int devid, int gen)
> > > +{
> > > + const struct pci_device *p,
> > > + *pend = pciids + sizeof(pciids) / sizeof(pciids[0]);
> > > +
> > > + for (p = pciids; p < pend; p++) {
> > > + /* PCI IDs are sorted */
> > > + if (p->gen < gen)
> > > + break;
> >
> > If we have lots of gen with lots of subids, a binary search for gen
> > would be sensible. However, do we need this function? Do we not just
> > convert everyone over to a lookup of pci-id on entry?
>
> in some places we need the single IS_GEN9(). The advantage of using this
> function rather than intel_get_genx() is that it can be faster due to
> stopping here, or doing a binary search as you pointed out.
> With intel_get_genx we don't have this. IS_GEN9() is may be called in
> non-initialization code paths, so IMO its worth.
>
> What we *can* do here instead is: guarantee all codepaths will occur
> after the call to drm_intel_bufmgr_gem_init() then remove all macros and
> just implement a single function that checks the "cached value".
That would be similar to how we handle elsewhere. But there's no need to
jump there in one series.
> > Idle thought
> > #ifdef SELFTEST
> > int main(void)
> > {
> > /* check pci-ids are ordered by gen */
> > }
> > #endif
>
> $ git grep SELFTEST
> $
>
> you do know this is a patch for libdrm, right?
Wouldn't be that hard to add a check_PROGRAMS target with a -DSELFTEST.
It was just an idle thought if you cared to improve the standard of a
stagnant library. It might as well retire with grace ;)
-Chris
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