Re: [PATCH v8 3/4] iommu/arm-smmu-v3: Standardize ATS enablement failure reporting

[Pranjal Shrivastava]

On Fri, Jun 12, 2026 at 10:36:38AM -0300, Jason Gunthorpe wrote:
> On Thu, Jun 04, 2026 at 06:21:15PM +0000, Pranjal Shrivastava wrote:
> > Update arm_smmu_enable_ats() to wrap the pci_enable_ats() call in
> > WARN_ON(). Since probe-time checks now preclude configuration errors
> > any failure during hardware enablement is considered a kernel bug.
> > 
> > Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
> > Signed-off-by: Pranjal Shrivastava <praan@xxxxxxxxxx>
> > ---
> >  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> 
> > +	 /*
> > +	  * Since pci_prepare_ats() has already verified the HW capability
> > +	  * and programmed the STE, pci_enable_ats() should not fail here.
> > +	  */
> > +	if (WARN_ON(pci_enable_ats(pdev, stu)))
> >  		dev_err(master->dev, "Failed to enable ATS (STU %zu)\n", stu);
> >  }
> 
> I would fold the dev_err string into the WARN though

Ack. Sent out a v9:

https://lore.kernel.org/all/20260615235037.259909-1-praan@xxxxxxxxxx/

Thanks,
Praan