Hi Sricharan, On Thu, May 18, 2017 at 08:24:16PM +0530, Sricharan R wrote: > While deferring the probe of IOMMU masters, xlate and > add_device callbacks called from iort_iommu_configure > can pass back error values like -ENODEV, which means > the IOMMU cannot be connected with that master for real > reasons. Before the IOMMU probe deferral, all such errors > were ignored. Now all those errors are propagated back, > killing the master's probe for such errors. Instead ignore > all the errors except EPROBE_DEFER, which is the only one > of concern and let the master work without IOMMU, thus > restoring the old behavior. > > Fixes: 5a1bb638d567 ("drivers: acpi: Handle IOMMU lookup failure with deferred probing or error") > Signed-off-by: Sricharan R <sricharan@xxxxxxxxxxxxxx> > --- > [V4] Added this patch newly. > > drivers/acpi/arm64/iort.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index c5fecf9..16e101f 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -782,6 +782,12 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev) > if (err) > ops = ERR_PTR(err); > > + /* Ignore all other errors apart from EPROBE_DEFER */ > + if (IS_ERR(ops) && (PTR_ERR(ops) != -EPROBE_DEFER)) { > + dev_dbg(dev, "Adding to IOMMU failed: %ld\n", PTR_ERR(ops)); > + ops = NULL; > + } > + > return ops; > } > It is getting a bit convoluted. Is not it better to propagate the error back and let acpi_dma_configure() make a decision accordingly ? Something like: -- >8 -- diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index e39ec7b..3a10d757 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1371,8 +1371,8 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) iort_set_dma_mask(dev); iommu = iort_iommu_configure(dev); - if (IS_ERR(iommu)) - return PTR_ERR(iommu); + if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER) + return -EPROBE_DEFER; size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); /* -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html