Re: [PATCH v3 6/6] iommu: Propagate ret for a potential soft failure EINVAL

On Tue, Sep 20, 2022 at 06:50:22AM +0000, Tian, Kevin wrote:

External email: Use caution opening links or attachments

quoted

From: Nicolin Chen <redacted>
Sent: Thursday, September 15, 2022 3:59 PM

Following the new rules in include/linux/iommu.h kdocs, EINVAL now can be
used to indicate that domain and device are incompatible by a caller that
treats it as a soft failure and tries attaching to another domain.

Either mtk_iommu or virtio driver has a place that returns a hard failure
instead of the return value from the function call, where an incompatible
errno EINVAL could potentially occur.

in both cases there is no EINVAL returned from the calling stack

IMHO error propagation is the right way even w/o talking about EINVAL
otherwise we may miss ENOMEM etc.

OK. I changed to:

The mtk_iommu and virtio drivers have places in the ->attach_dev callback
functions that return hardcode errnos instead of the returned values, but
callers of these ->attach_dv callback functions may care. Propagate them
directly without the extra conversions.

quoted

Propagate the real return value to not miss a potential soft failure.

Signed-off-by: Nicolin Chen <redacted>

Apart from that comment,

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Added this too. Thanks!

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel