On Wed, Jan 09, 2013 at 02:21:50PM -0800, Bill Paul wrote: > Of all the gin joints in all the towns in all the world, Michael S. Tsirkin > had to walk into mine at 14:07:53 on Wednesday 09 January 2013 and say: > > > On Wed, Jan 09, 2013 at 01:50:39PM -0600, Anthony Liguori wrote: > > > I figured this would be the case but this is where a comment in the code > > > or commit message would have helped a lot in avoiding future confusion. > > > > > > Regards, > > > > > > Anthony Liguori > > > > I just sent a documentation patch, please take a look. > > Thanks! > > Well, strictly speaking, VxWorks doesn't rely on the ICS behavior anymore, > but > it prefers it. I ran into problems with VMware and Simics too, as they also > don't emulate the ICS behavior, and getting that fixed was more of an uphill > battle. So as a compromise I added a check to the driver to see if the ICS > register has 'real hardware behavior' or 'emulated behavior' and made it use > an alternate interrupt handling scheme in the emulated case. The alternate > scheme is a little less efficient than the ICS scheme in some cases (mainly > when the PRO/1000 device's interrupt is shared), but it still handles > interrupts reliably. > > That's a minor nit though. I'm fine with the comments as is. I just didn't > want you do think VxWorks was completely brain damaged. :)
I guess I'll change it to "The VxWorks PRO/1000 driver uses this behaviour." > Note that I don't think VMware emulates the 'flexible RX mode' descriptor > mechanism for the PRO/100 either, because the non-NDAed PRO/100 manual > doesn't > bother to mention it exists. I think this is something that was fixed in QEMU > but I haven't had a chance to test it in a while. There's a similar problem > with simulated the AMD PCnet/PCI devices (they only support the > 'configuration > block' setup method -- for the older non-PCI LANCE chips that was the only > way > to configure them but PCI devices starting with the am97c970 can be > configured > just by setting up registers). > > Honestly I'm surprised I still have all my hair and that it's still the same > color. > > -Bill Yes virtio is much easier. All bugs there are our own. > -- > ============================================================================= > -Bill Paul (510) 749-2329 | Member of Technical Staff, > wp...@windriver.com | Master of Unix-Fu - Wind River Systems > ============================================================================= > "I put a dollar in a change machine. Nothing changed." - George Carlin > =============================================================================
