From: Mark Brown <broonie@kernel.org>
To: Jisheng Zhang <jszhang@kernel.org>
Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] spi: dw: Fix missing smp_mb() in dw_spi_exec_mem_op
Date: Tue, 13 Oct 2026 23:10:09 +0100 [thread overview]
Message-ID: <f4fe920a-7b2b-4c6d-bf41-a7935e6e5574@sirena.org.uk> (raw)
In-Reply-To: <20261010151529.30590-1-jszhang@kernel.org>
[-- Attachment #1: Type: text/plain, Size: 621 bytes --]
On Sat, Oct 10, 2026 at 11:15:29PM +0800, Jisheng Zhang wrote:
> Similar as commit bfda044533b2 ("spi: dw: use "smp_mb()" to avoid
> sending spi data error"), we also need the smp_mb() in
> dw_spi_exec_mem_op() after setting up the members in "dws" to ensure
> the data change is visible for all CPUs.
Which other CPUs are we worried about here? Unlike the regular SPI path
which can use DMA and interrupts for the exec_op() stuff we only do PIO
and have interrupts masked during the actual transfer. If the task
migrates I'd expect that to have all the required barriers, but
otherwise it all looks single threaded.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2026-10-13 22:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-10 15:15 Jisheng Zhang
2026-10-13 22:10 ` Mark Brown [this message]
2026-10-14 4:15 ` Jisheng Zhang
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=f4fe920a-7b2b-4c6d-bf41-a7935e6e5574@sirena.org.uk \
--to=broonie@kernel.org \
--cc=jszhang@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.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
all inboxes | Powered by JetHome®