I have been hitting EEH address errors testing this with some network
cards which map/unmap DMA addresses more frequently. For example:
PHB4 PHB#5 Diag-data (Version: 1)
brdgCtl: 00000002
RootSts: 00060020 00402000 a0220008 00100107 00000800
PhbSts: 0000001c00000000 0000001c00000000
Lem: 0000000100000080 0000000000000000 0000000000000080
PhbErr: 0000028000000000 0000020000000000 2148000098000240 a008400000000000
RxeTceErr: 2000000000000000 2000000000000000 c000000000000000 0000000000000000
PblErr: 0000000000020000 0000000000020000 0000000000000000 0000000000000000
RegbErr: 0000004000000000 0000004000000000 61000c4800000000 0000000000000000
PE[000] A/B: 8300b03800000000 8000000000000000
Interestingly the PE[000] A/B data is the same across different cards
and drivers.
- Alistair
On Wednesday, 5 June 2019 11:11:06 PM AEST Shawn Anastasio wrote:
> On 5/30/19 2:03 AM, Alexey Kardashevskiy wrote:
> > This is an attempt to allow DMA masks between 32..59 which are not large
> > enough to use either a PHB3 bypass mode or a sketchy bypass. Depending
> > on the max order, up to 40 is usually available.
> >
> >
> > This is based on v5.2-rc2.
> >
> > Please comment. Thanks.
>
> I have tested this patch set with an AMD GPU that's limited to <64bit
> DMA (I believe it's 40 or 42 bit). It successfully allows the card to
> operate without falling back to 32-bit DMA mode as it does without
> the patches.
>
> Relevant kernel log message:
> ```
> [ 0.311211] pci 0033:01 : [PE# 00] Enabling 64-bit DMA bypass
> ```
>
> Tested-by: Shawn Anastasio <sh...@anastas.io>
