From: Pranjal Shrivastava <praan@google.com>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: iommu@lists.linux.dev, linux-pci@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
Will Deacon <will@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
David Woodhouse <dwmw2@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Robin Murphy <robin.murphy@arm.com>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
David Matlack <dmatlack@google.com>,
Samiullah Khawaja <skhawaja@google.com>,
Daniel Mentz <danielmentz@google.com>,
Pasha Tatashin <pasha.tatashin@soleen.com>,
Mostafa Saleh <smostafa@google.com>
Subject: Re: [PATCH v6 3/6] PCI/ATS: Mandate checking pci_ats_supported() before pci_prepare_ats()
Date: Sun, 31 May 2026 17:06:20 +0000 [thread overview]
Message-ID: <ahxqjLg3yRzWhgqE@google.com> (raw)
In-Reply-To: <ahoLccjQvmoE90sx@Asurada-Nvidia>
On Fri, May 29, 2026 at 02:56:01PM -0700, Nicolin Chen wrote:
> On Fri, May 29, 2026 at 11:12:05AM +0000, Pranjal Shrivastava wrote:
> > Currently, pci_prepare_ats() internally calls pci_ats_supported() and
> > returns -EINVAL if the device does not support ATS. While this provides
> > a silent safety check, it conflates support detection with configuration.
> >
> > Update pci_prepare_ats() to wrap the internal pci_ats_supported check in
> > a WARN_ON(). This mandates all callers to call pci_prepare_ats() only if
> > the function supports ATS.
> >
> > Update the function documentation to mention that callers must verify
> > ATS support (via pci_ats_supported()) before calling pci_prepare_ats().
> >
> > Suggested-by: Baolu Lu <baolu.lu@linux.intel.com>
> > Signed-off-by: Pranjal Shrivastava <praan@google.com>
>
> Sashiko pointed out a bisect issue. So, you might want to reorder
> a bit. The patch itself looks good to me.
>
Ack. I'll re-order for bisectibility.
> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Thanks!
Praan
next prev parent reply other threads:[~2026-05-31 17:06 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-29 11:12 [PATCH v6 0/6] iommu: Standardize ATS robustness and state tracking Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 1/6] PCI/ATS: Ensure pci_ats_supported() is PF-aware for VFs Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 2/6] PCI/ATS: Validate STU for VFs in pci_prepare_ats() Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 3/6] PCI/ATS: Mandate checking pci_ats_supported() before pci_prepare_ats() Pranjal Shrivastava
2026-05-29 21:56 ` Nicolin Chen
2026-05-31 17:06 ` Pranjal Shrivastava [this message]
2026-05-29 11:12 ` [PATCH v6 4/6] iommu/arm-smmu-v3: Standardize ATS enablement failure reporting Pranjal Shrivastava
2026-05-29 21:51 ` Nicolin Chen
2026-05-31 17:13 ` Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 5/6] iommu/vt-d: Fail probe on ATS configuration failure Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 6/6] iommu/amd: " Pranjal Shrivastava
2026-06-01 6:00 ` Ankit Soni
2026-06-01 6:20 ` Pranjal Shrivastava
2026-06-01 8:17 ` Ankit Soni
2026-06-01 10:35 ` Pranjal Shrivastava
2026-06-01 9:28 ` Vasant Hegde
2026-06-01 10:41 ` Pranjal Shrivastava
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ahxqjLg3yRzWhgqE@google.com \
--to=praan@google.com \
--cc=baolu.lu@linux.intel.com \
--cc=bhelgaas@google.com \
--cc=danielmentz@google.com \
--cc=dmatlack@google.com \
--cc=dwmw2@infradead.org \
--cc=iommu@lists.linux.dev \
--cc=jgg@ziepe.ca \
--cc=joro@8bytes.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=nicolinc@nvidia.com \
--cc=pasha.tatashin@soleen.com \
--cc=robin.murphy@arm.com \
--cc=skhawaja@google.com \
--cc=smostafa@google.com \
--cc=suravee.suthikulpanit@amd.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox