On Monday 19 January 2009, Hidetoshi Seto wrote:
> Rafael J. Wysocki wrote:
> > On Saturday 17 January 2009, Rafael J. Wysocki wrote:
> (snip)
> >> If MSI-X are supported, it allocates as many vectors as there are entries
> >> in the port's MSI-X table, but no more than 32, and figures out which of them
> >> will be used for the port services.
> >
> > The patch didn't check which services are available during the MSI-X set up
> > which was wrong.
> >
> > Also, in the meantime, i thought it might be a good idea to free the interrupt
> > routing table entries that aren't going to be used after all.
> >
> > The patch below adds this to the previous version and checks for the
> > availability of port services in the MSI-X setup resume. I hope it will
> > be acceptable to everyone.
> >
[--snip--]
> > + /*
> > + * Allocate as many entries as the device wants temporarily, so that we
> > + * can check which of them will be useful.
> > + */
> > + for (i = 0; i < nr_entries; i++)
> > + msix_entries[i].entry = i;
>
> /*
> * So, if msix_entries is correctly equal to the number of entries this
> * port actually uses, we'll happily go through without using trick.
> */
Good point!
> > +
> > + status = pci_enable_msix(dev, msix_entries, nr_entries);
> > + if (status)
> > + goto Exit;
[--snip--]
> > +
>
> /* Are there any unused entries? */
> if (nr_allocated > nvec) {
> /* this port have extra entries not for services we know... */
>
> > + /* Drop the temporary MSI-X setup */
> > + pci_disable_msix(dev);
Yes, I'm going to do that.
> > + /* Now allocate the MSI-X vectors for real */
> > + status = pci_enable_msix(dev, msix_entries, nvec);
> > + if (status)
> > + goto Error;
>
> /*
> * World have broken hardwares, so even spec says numbers are constant,
> * it would be better to re-check registers after 2nd pci_enable_msix.
> * Or we just skip this. (However this was what your concern, Rafael?)
> */
> if (func_foo_do_paranoia_check(dev, msix_entries, nvec))
> goto Error;
Well, I think let's not do it for now. If there's a system that actually
breaks here, then we can introduce the extra checking.
Thanks,
Rafael
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