From: Jason Gunthorpe <jgg@ziepe.ca>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Bjorn Helgaas <helgaas@kernel.org>,
Will McVicker <willmcvicker@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Danilo Krummrich <dakr@kernel.org>,
"Rob Herring (Arm)" <robh@kernel.org>,
Lorenzo Pieralisi <lpieralisi@kernel.org>,
Joerg Roedel <jroedel@suse.de>,
Bjorn Helgaas <bhelgaas@google.com>,
iommu@lists.linux.dev, Saravana Kannan <saravanak@google.com>,
kernel-team@android.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] platform: Fix race condition during DMA configure at IOMMU probe time
Date: Wed, 23 Apr 2025 13:57:11 -0300 [thread overview]
Message-ID: <20250423165711.GG1213339@ziepe.ca> (raw)
In-Reply-To: <4129dca9-07fa-4b9d-a7d8-de7561d509e7@arm.com>
On Wed, Apr 23, 2025 at 04:50:29PM +0100, Robin Murphy wrote:
> Indeed in my half-written version of this patch I was leaning towards
> removing the drv variable altogether (just doing
> to_x_driver(dev->driver)->driver_managed_dma inline), or at least doing the
> same as Will's previous diff. I figure the one-liner replacing
> "!dev->driver" with "!&drv->driver" would be too disgustingly non-obvious
> for anyone else's tastes...
The READ_ONCE alerts the reader that something weird is going on here :\
> For consistency we should really fix all the buses the same way - sorry for
> the bother (I can write up the other patches if you'd like). FWIW this part
> really was the most temporary stopgap, as my planned next step is to propose
> moving driver_managed_dma and the use_default_domain() call up into the
> driver core and so removing all this bus-level code anyway, hence trying to
> minimise the effort spent churning it. Oh well.
It started out this way but Greg really didn't want it, so this was
the compromise. Perhaps you can convince Greg of the merit.
Jason
next prev parent reply other threads:[~2025-04-23 16:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-22 23:26 [PATCH v1] platform: Fix race condition during DMA configure at IOMMU probe time Will McVicker
2025-04-23 15:08 ` Bjorn Helgaas
2025-04-23 15:50 ` Robin Murphy
2025-04-23 16:57 ` Jason Gunthorpe [this message]
2025-04-23 17:27 ` William McVicker
2025-04-23 16:58 ` Jason Gunthorpe
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=20250423165711.GG1213339@ziepe.ca \
--to=jgg@ziepe.ca \
--cc=bhelgaas@google.com \
--cc=dakr@kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=helgaas@kernel.org \
--cc=iommu@lists.linux.dev \
--cc=jroedel@suse.de \
--cc=kernel-team@android.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lpieralisi@kernel.org \
--cc=rafael@kernel.org \
--cc=robh@kernel.org \
--cc=robin.murphy@arm.com \
--cc=saravanak@google.com \
--cc=willmcvicker@google.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.