On 6/12/19 1:16 AM, Oliver O'Halloran wrote:
On Wed, Jun 12, 2019 at 3:06 PM Shawn Anastasio <sh...@anastas.io> wrote:
On 6/5/19 11:11 PM, 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>
After a few days of further testing, I've started to run into stability
issues with the patch applied and used with an AMD GPU. Specifically,
the system sometimes spontaneously crashes. Not just EEH errors either,
the whole system shuts down in what looks like a checkstop.
Any specific workload? Checkstops are harder to debug without a system
in the failed state so we'd need to replicate that locally to get a
decent idea what's up.
I haven't been able to pinpoint the exact cause. The first time it
happened was after about 4 days of uptime while playing a 1080p
video in mpv. The second time was about 5 minutes after booting up
while restoring a firefox session.
