[Intel-gfx] [PATCH i-g-t] lib: Pass device fd to gem_mmappable_aperture_size()

[Chris Wilson]

Quoting Chang, Yu bruce (2020-12-14 21:52:10)
> 
> >
> >From: Chris Wilson <chris at chris-wilson.co.uk>
> >Sent: Monday, December 14, 2020 12:48 PM
> >To: Chang, Yu bruce; intel-gfx at lists.freedesktop.org
> >Cc: igt-dev@
> >Subject: Re: [Intel-gfx] [PATCH i-g-t] lib: Pass device fd to
> gem_mmappable_aperture_size()
> > 
> >Quoting Chang, Yu bruce (2020-12-14 18:45:04)
> >> +/**
> >> + * gem_mappable_aperture_size:
> >> + *
> >> + * Feature test macro to query the kernel for the mappable gpu aperture
> size.
> >> + * This is the area available for GTT memory mappings.
> >> + *
> > + * Returns: The mappable gtt address space size.
> > + */
> > +uint64_t gem_mappable_aperture_size(int fd)
> > +{
> > +       struct pci_device *pci_dev = igt_device_get_pci_device(fd);
> > 
> > Does it make sense to eliminate the function intel_get_pci_device() if not
> > being used anymore? But it can be a separate patch.
> >
> >It's still used by tools. The complication there is that we mostly
> >need to lookup the pci device without loading i915.ko. 
> >-Chris
> >
> 
> That makes sense.
> 
> Then we need to make sure not start from a fix slot to look for GPU device in
> the intel_get_pci_device() below as
> it may not work for a discrete GPU as that slot can be a non-vga device but
> with vendor_id 0x8086.
> 
>         pci_dev = pci_device_find_by_slot(0, 0, 2, 0);
>         if (pci_dev == NULL || pci_dev->vendor_id != 0x8086) {
> 
> So, either add extra check to make sure it is VGA class or always use 
> pci_device_next to search.

It's held true for ~20 years :)

I hear you; for the remaining users, they should probably use the lsgpu
interface to pick the right device to work on (and remove
intel_get_pci_device).

tools/intel_audio_dump.c
tools/intel_backlight.c
tools/intel_display_poller.c
tools/intel_forcewaked.c
tools/intel_gpu_time.c
tools/intel_gtt.c
tools/intel_infoframes.c
tools/intel_lid.c
tools/intel_panel_fitter.c
tools/intel_reg.c
tools/intel_reg_checker.c
tools/intel_watermark.c

A few of those could even be retired.
-Chris