Re: [PATCH] iommu/dma: fix incorrect error return on iommu deferred attach

From: John Garry
Date: Mon Nov 01 2021 - 05:24:20 EST


On 27/10/2021 18:47, Logan Gunthorpe wrote:
scsi_dma_map() was reporting a failure during boot on an AMD machine
with the IOMMU enabled.

scsi_dma_map failed: request for 36 bytes!

The issue was tracked down to a mistake in logic: should not return
an error if iommu_deferred_attach() returns zero.

Reported-by: Marshall Midden<marshallmidden@xxxxxxxxx>
Fixes: dabb16f67215 ("iommu/dma: return error code from iommu_dma_map_sg()")
Link:https://lore.kernel.org/all/CAD2CkAWjS8=kKwEEN4cgVNjyFORUibzEiCUA-X+SMtbo0JoMmA@xxxxxxxxxxxxxx
Signed-off-by: Logan Gunthorpe<logang@xxxxxxxxxxxx>
Cc: Joerg Roedel<joro@xxxxxxxxxx>
Cc: Will Deacon<will@xxxxxxxxxx>

Seems reasonable, FWIW:
Reviewed-by: John Garry <john.garry@xxxxxxxxxx>