On Sun, Jun 12, 2022 at 04:43:25PM +0200, Hans de Goede wrote: > Clipping the bridge windows directly from pci_acpi_root_prepare_resources() > instead of clipping from arch_remove_reservations(), has a number of > unforseen consequences. > > If there is an e820 reservation in the middle of a bridge window, then > the smallest of the 2 remaining parts of the window will be also clipped > off. Where as the previous code would clip regions requested by devices, > rather then the entire window, leaving regions which were either entirely > above or below a reservation in the middle of the window alone. > > E.g. on the Steam Deck this leads to this log message: > > acpi PNP0A08:00: clipped [mem 0x80000000-0xf7ffffff window] to [mem 0xa0100000-0xf7ffffff window] > > which then gets followed by these log messages: > > pci 0000:00:01.2: can't claim BAR 14 [mem 0x80600000-0x806fffff]: no compatible bridge window > pci 0000:00:01.3: can't claim BAR 14 [mem 0x80500000-0x805fffff]: no compatible bridge window > > and many more of these. Ultimately this leads to the Steam Deck > no longer booting properly, so revert the change. > > Note this is not a clean revert, this revert keeps the later change > to make the clipping dependent on a new pci_use_e820 bool, moving > the checking of this bool to arch_remove_reservations(). It does _not_ fix the Intel MID case. It requires to have my patch applied as well. So the difference as I see is the flags checking. I believe that you still need to have it in case pci_use_e820 == true. But it might be that I missed an importan detail. -- With Best Regards, Andy Shevchenko
