From: "ni.liqiang" <ni_liqiang@126.com>
To: will@kernel.org, danielmentz@google.com
Cc: iommu@lists.linux.dev, jin.qi@zte.com.cn, joro@8bytes.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, ni.liqiang@zte.com.cn,
niliqiang.io@gmail.com, robin.murphy@arm.com
Subject: Re: [PATCH] drivers/iommu: Ensure that the queue base address is successfully written during SMMU initialization.
Date: Sat, 24 Feb 2024 00:20:10 +0800 [thread overview]
Message-ID: <20240223162010.6884-1-ni_liqiang@126.com> (raw)
In-Reply-To: <20240221160849.GB7362@willie-the-truck>
> (Disclaimer: I don't know what a CCG port is)
CCG(CXL Gateway) is a part of the CMN700 Coherent Mesh Network. It plays
a crucial role in facilitating cross-die access in a multi-chip system.
> Hmmm. The part that doesn't make sense to me here is that migrating between
> CPUs implies context-switching, and we have a DSB on that path in
> __switch_to(). So why would adding barriers to the driver help? Maybe it
> just changes the timing?
This is very likely. Through our experiments, adding a delay before CMDQEN
does not reproduce the failure of writing to the CMDQ base register.
> I'm not sure what you're proposing, but I don't think Linux should be
> changed to accomodate this.
I am very grateful for the responses from both of you experts. We will
continue to check the current hardware configuration of the system
and attempt to fix this issue.
Once again, I express my thanks. Thank you.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
prev parent reply other threads:[~2024-02-23 16:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-18 5:02 [PATCH] drivers/iommu: Ensure that the queue base address is successfully written during SMMU initialization ni.liqiang
2024-02-19 5:44 ` Daniel Mentz
2024-02-19 9:17 ` Will Deacon
2024-02-21 15:26 ` ni.liqiang
2024-02-21 16:08 ` Will Deacon
2024-02-23 16:20 ` ni.liqiang [this message]
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=20240223162010.6884-1-ni_liqiang@126.com \
--to=ni_liqiang@126.com \
--cc=danielmentz@google.com \
--cc=iommu@lists.linux.dev \
--cc=jin.qi@zte.com.cn \
--cc=joro@8bytes.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ni.liqiang@zte.com.cn \
--cc=niliqiang.io@gmail.com \
--cc=robin.murphy@arm.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