After 8b3517f88ff2 ("PCI: loongson: Prevent LS7A MRRS increases") backported to stable, we have received multiple regression reports including one from Debian build farm[1] that some systems failed to initialize some PCIe devices. I was able to reproduce on one of my Loongson-3A4000+7A system. It seems like the root cause is firmware on those systems didn't set MRRS properly but 8b3517f88ff2 ("PCI: loongson: Prevent LS7A MRRS increases") assumed firmware's maximum MRRS is always valid. [1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1035587
Mark as regression.
(In reply to jiaxun.yang from comment #0) > After 8b3517f88ff2 ("PCI: loongson: Prevent LS7A MRRS increases") backported > to stable, we have received multiple regression reports including one from > Debian build farm[1] that some systems failed to initialize some PCIe > devices. > > I was able to reproduce on one of my Loongson-3A4000+7A system. It seems > like the root cause is firmware on those systems didn't set MRRS properly > but 8b3517f88ff2 ("PCI: loongson: Prevent LS7A MRRS increases") assumed > firmware's maximum MRRS is always valid. > > [1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1035587 I see that you're about to post your patch that (supposedly) fixes this regression here [1] . Where is one? [1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1035587#55