On Mon, Nov 16, 2020 at 8:36 AM Will Deacon <will@xxxxxxxxxx> wrote: > On Mon, Nov 16, 2020 at 04:59:36PM +0100, Thierry Reding wrote: > > On Fri, Nov 06, 2020 at 04:27:10AM +0000, John Stultz wrote: > > Unfortunately, the ARM SMMU module will eventually end up being loaded > > once the root filesystem has been mounted (for example via SDHCI or > > Ethernet, both with using just plain, non-IOMMU-backed DMA API) and then > > initialize, configuring as "fault by default", which then results from a > > slew of SMMU faults from all the devices that have previously configured > > themselves without IOMMU support. > > I wonder if fw_devlink=on would help here? > > But either way, I'd be more inclined to revert this change if it's causing > problems for !QCOM devices. > > Linus -- please can you drop this one (patch 3/3) for now, given that it's > causing problems? Agreed. Apologies again for the trouble. I do feel like the probe timeout to handle optional links is causing a lot of the trouble here. I expect fw_devlink would solve this, but it may be awhile before it can be always enabled. I may see about pushing the default probe timeout value to be a little further out than init (I backed away from my last attempt as I didn't want to cause long (30 second) delays for cases like NFS root, but maybe 2-5 seconds would be enough to make things work better for everyone). thanks -john
