All of lore.kernel.org
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: Li Yang <leoyang.li@nxp.com>
Cc: arm-soc <arm@kernel.org>, SoC Team <soc@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	Ioana Ciornei <ioana.ciornei@nxp.com>,
	Diana Craciun <diana.craciun@nxp.com>
Subject: Re: [GIT PULL] soc/fsl drivers changes for fix(v5.15)
Date: Fri, 22 Oct 2021 21:54:40 +0200	[thread overview]
Message-ID: <CAK8P3a35adaG9OzWWFSvjJcQo+hEnEJuLCL-8je-m+78JfjWxQ@mail.gmail.com> (raw)
In-Reply-To: <20211022010027.11866-1-leoyang.li@nxp.com>

On Fri, Oct 22, 2021 at 3:00 AM Li Yang <leoyang.li@nxp.com> wrote:
> ----------------------------------------------------------------
> NXP/FSL SoC driver fixes for v5.15

> - fix qbman alignment error in the virtualization context

This patch looks very suspicious to me, I don't think it's generally safe to
use memcpy_toio() on a normal pointer, as the __iomem tokens may
be in a separate address range, even though this currently works
on arm64. Adding the  (__iomem void *) cast without a comment that
explains why it's added seems similarly wrong, and finally the
changeset text does not seem to match what the code does:

According to the text, the pointer is to a virtual address mapped as
"device memory" (i.e. PROT_DEVICE_nGnRE or PROT_DEVICE_nGnRnE),
but the code suggests it's actually write-combining normal
(PROT_NORMAL_NC).

I don't see any discussion of this patch on the mailing list either, so
please resend the pull request without this patch, while we try to figure
out what the driver should actually be doing here.

       Arnd

WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: Li Yang <leoyang.li@nxp.com>
Cc: arm-soc <arm@kernel.org>, SoC Team <soc@kernel.org>,
	 Linux ARM <linux-arm-kernel@lists.infradead.org>,
	 Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	 Ioana Ciornei <ioana.ciornei@nxp.com>,
	Diana Craciun <diana.craciun@nxp.com>
Subject: Re: [GIT PULL] soc/fsl drivers changes for fix(v5.15)
Date: Fri, 22 Oct 2021 21:54:40 +0200	[thread overview]
Message-ID: <CAK8P3a35adaG9OzWWFSvjJcQo+hEnEJuLCL-8je-m+78JfjWxQ@mail.gmail.com> (raw)
Message-ID: <20211022195440.OLf97BYG6_Rm5YFTE_DYvFbIMsZIxxXAgWTMS0KWIFM@z> (raw)
In-Reply-To: <20211022010027.11866-1-leoyang.li@nxp.com>

On Fri, Oct 22, 2021 at 3:00 AM Li Yang <leoyang.li@nxp.com> wrote:
> ----------------------------------------------------------------
> NXP/FSL SoC driver fixes for v5.15

> - fix qbman alignment error in the virtualization context

This patch looks very suspicious to me, I don't think it's generally safe to
use memcpy_toio() on a normal pointer, as the __iomem tokens may
be in a separate address range, even though this currently works
on arm64. Adding the  (__iomem void *) cast without a comment that
explains why it's added seems similarly wrong, and finally the
changeset text does not seem to match what the code does:

According to the text, the pointer is to a virtual address mapped as
"device memory" (i.e. PROT_DEVICE_nGnRE or PROT_DEVICE_nGnRnE),
but the code suggests it's actually write-combining normal
(PROT_NORMAL_NC).

I don't see any discussion of this patch on the mailing list either, so
please resend the pull request without this patch, while we try to figure
out what the driver should actually be doing here.

       Arnd

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2021-10-22 19:55 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-22  1:00 [GIT PULL] soc/fsl drivers changes for fix(v5.15) Li Yang
2021-10-22  1:00 ` Li Yang
2021-10-22  1:00 ` [GIT PULL] soc/fsl drivers changes for next(v5.16) Li Yang
2021-10-22  1:00   ` Li Yang
2021-10-22 20:10   ` patchwork-bot+linux-soc
2021-10-22 19:54 ` Arnd Bergmann [this message]
2021-10-22 19:54   ` [GIT PULL] soc/fsl drivers changes for fix(v5.15) Arnd Bergmann

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=CAK8P3a35adaG9OzWWFSvjJcQo+hEnEJuLCL-8je-m+78JfjWxQ@mail.gmail.com \
    --to=arnd@arndb.de \
    --cc=arm@kernel.org \
    --cc=diana.craciun@nxp.com \
    --cc=ioana.ciornei@nxp.com \
    --cc=leoyang.li@nxp.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=shawnguo@kernel.org \
    --cc=soc@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 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.