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. > Perhaps some subtle corruption is occurring?
