On Tue, May 11, 2021 at 01:40:20AM +0200, Maximilian Luz wrote:
> The Microsoft Surface Pro X has host bridges defined as
>
> Name (_HID, EisaId ("PNP0A08") /* PCI Express Bus */) // _HID: Hardware ID
> Name (_CID, EisaId ("PNP0A03") /* PCI Bus */) // _CID: Compatible ID
>
> Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
> {
> Name (RBUF, ResourceTemplate ()
> {
> Memory32Fixed (ReadWrite,
> 0x60200000, // Address Base
> 0x01DF0000, // Address Length
> )
> WordBusNumber (ResourceProducer, MinFixed, MaxFixed, PosDecode,
> 0x0000, // Granularity
> 0x0000, // Range Minimum
> 0x0001, // Range Maximum
> 0x0000, // Translation Offset
> 0x0002, // Length
> ,, )
> })
> Return (RBUF) /* \_SB_.PCI0._CRS.RBUF */
> }
>
> meaning that the memory resources aren't (explicitly) defined as
> "producers", i.e. host bridge windows.
>
> Commit 8fd4391ee717 ("arm64: PCI: Exclude ACPI "consumer" resources from
> host bridge windows") introduced a check that removes such resources,
> causing BAR allocation failures later on:
>
> [ 0.150731] pci 0002:00:00.0: BAR 14: no space for [mem size 0x00100000]
> [ 0.150744] pci 0002:00:00.0: BAR 14: failed to assign [mem size 0x00100000]
> [ 0.150758] pci 0002:01:00.0: BAR 0: no space for [mem size 0x00004000 64bit]
> [ 0.150769] pci 0002:01:00.0: BAR 0: failed to assign [mem size 0x00004000 64bit]
>
> This eventually prevents the PCIe NVME drive from being accessible.
>
> On x86 we already skip the check for producer/window due to some history
> with negligent firmware. It seems that Microsoft is intent on continuing
> that history on their ARM devices, so let's drop that check here too.
>
> Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
> ---
>
> Please note: I am not sure if this is the right way to fix that, e.g. I
> don't know if any additional checks like on IA64 or x86 might be
> required instead, or if this might break things on other devices. So
> please consider this more as a bug report rather than a fix.
>
> Apologies for the re-send, I seem to have unintentionally added a blank
> line before the subject.
>
> ---
> arch/arm64/kernel/pci.c | 14 --------------
> 1 file changed, 14 deletions(-)
Adding Lorenzo to cc, as he'll have a much better idea about this than me.
This is:
https://lore.kernel.org/r/20210510234020.1330087-1-luzmaximilian@xxxxxxxxx
Will
