From: Arnd Bergmann <arnd@arndb.de>
To: 宋强 <songqiang@uniontech.com>
Cc: Matthew Wilcox <willy@infradead.org>, sam <sam@ravnborg.org>,
"b.zolnierkie" <b.zolnierkie@samsung.com>,
penguin-kernel <penguin-kernel@i-love.sakura.ne.jp>,
"george.kennedy" <george.kennedy@oracle.com>,
tzimmermann <tzimmermann@suse.de>, jgg <jgg@ziepe.ca>,
dri-devel <dri-devel@lists.freedesktop.org>,
linux-fbdev <linux-fbdev@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Re: [PATCH] drivers/video/fbdev/core/fbmem.c: add pointer judgment
Date: Thu, 20 May 2021 09:48:29 +0200 [thread overview]
Message-ID: <CAK8P3a2Pt+e3fbfWxJru7O-Np9u2u-_cVZqd5xBejLSraFYALQ@mail.gmail.com> (raw)
In-Reply-To: <1049640176.41531.1621490295842.JavaMail.xmail@localhost.localdomain>
> > On Wed, May 19, 2021 at 08:00:28PM +0800, songqiang wrote:
> > Signed-off-by: songqiang <songqiang@uniontech.com>
> From: "Matthew Wilcox <willy@infradead.org>"
> > You need to explain:
> >
> > - Why you think this patch is needed
> > - Did you observe a problem at runtime?
> > - Is this the output from some checking tool?
> > - Why this is the right way to address the problem
>
On Thu, May 20, 2021 at 7:58 AM 宋强 <songqiang@uniontech.com> wrote:
>
> I find null pointer bug when I debug the kernel of loongson，I think the function fb_set_suspend()
> add pointer judgment will more friendly.
When replying to emails on the list, please remember
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- use plain text email, html replies get dropped by many mailing lists.
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> [ 102.011018] Call Trace:
>
> [ 102.013443] [<ffffffff81068e10>] fb_set_suspend+0x50/0x80
> [ 102.018819] [<ffffffffc0061aa0>] loongson_drm_suspend+0x1a0/0x340 [loongson]
> [ 102.025827] [<ffffffffc0061c58>] loongson_pmops_freeze+0x18/0x40 [loongson]
> [ 102.032748] [<ffffffff81008fd4>] pci_pm_freeze+0x94/0x240
> [ 102.038114] [<ffffffff815377e0>] dpm_run_callback.isra.5+0x20/0x140
> [ 102.044341] [<ffffffff81539608>] __device_suspend+0x2c8/0x740
It looks like the check would actually belong into the loongson_drm driver.
The driver is not upstream yet, but I assume you have the source for it, so
try to fix the bug there and send the patch to the owners of that driver.
Arnd
prev parent reply other threads:[~2021-05-20 7:49 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-19 12:00 [PATCH] drivers/video/fbdev/core/fbmem.c: add pointer judgment songqiang
2021-05-19 12:16 ` Matthew Wilcox
[not found] ` <1049640176.41531.1621490295842.JavaMail.xmail@localhost.localdomain>
2021-05-20 7:48 ` Arnd Bergmann [this message]
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