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Date:   Wed, 8 Jun 2022 09:11:10 +0800
From:   Baoquan He <bhe@redhat.com>
To:     Rob Landley <rob@landley.net>, akpm@linux-foundation.org
Cc:     ysato@users.sourceforge.jp, dalias@libc.org,
        linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel test robot <lkp@intel.com>
Subject: Re: [PATCH] sh: cast away __iomem to remove sparse warning
Message-ID: <Yp/3Lq03+UVs9Bpv@MiWiFi-R3L-srv>
References: <20220507013411.74277-1-bhe@redhat.com>
 <YpS0C8tVG2E5jGSV@MiWiFi-R3L-srv>
 <c24579a3-74e4-1dbb-6237-d9e1a01e6e09@landley.net>
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On 06/07/22 at 05:56pm, Rob Landley wrote:
> 
> 
> On 5/30/22 07:09, Baoquan He wrote:
> > Hi,
> > 
> > On 05/07/22 at 09:34am, Baoquan He wrote:
> >> LKP reported a sparse warning in arch/sh/kernel/crash_dump.c during
> >> a kdump patchset reviewing:
> >> https://lore.kernel.org/all/202204082128.JKXXDGpa-lkp@intel.com/T/#u
> >> 
> >> ../arch/sh/kernel/crash_dump.c:23:36: sparse: warning: incorrect type in argument 1 (different address spaces)
> >> ../arch/sh/kernel/crash_dump.c:23:36: sparse:    expected void const *addr
> >> ../arch/sh/kernel/crash_dump.c:23:36: sparse:    got void [noderef] __iomem *
> >> 
> >> This warning happened when __iomem pointer is passed into fucntion
> >> which doesn't expect it. Casting away the __iomem can fix it.
> > 
> > This warning was reported by lkp during one patchset posted and
> > reviewing. Since it's not related to the patchset, I just sent it
> > separately so that later code change on arch/sh/kernel/crash_dump.c
> > won't trigger the lkp warning again.
> > 
> > [PATCH v5 RESEND 0/3] Convert vmcore to use an iov_iter
> > https://lore.kernel.org/all/20220408090636.560886-2-bhe@redhat.com/T/#u
> > 
> > Now the above patchset has been merged into linus's tree, please
> > consider taking this patch.
...... 
> Tested-by: Rob Landley <rob@landley.net>

Thanks for testing, Rob.

I guess SuperH arch has been in status of no maintenance, however some
generic code change may involve correspondant ARCH change so that we
have to touch arch/sh/.

Hi Andrew,

To avoid annoying warning when modifying crash_dump code, could you
pick this one?

Thanks
Baoquan