All of lore.kernel.org
 help / color / mirror / Atom feed
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

- avoid top-posting, see https://git-send-email.io/top-posting.html
- use plain text email, html replies get dropped by many mailing lists.

The information from your reply should be part of the patch description when
you send a patch, see
https://www.kernel.org/doc/html/v4.17/process/submitting-patches.html


> [  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

WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: 宋强 <songqiang@uniontech.com>
Cc: jgg <jgg@ziepe.ca>, linux-fbdev <linux-fbdev@vger.kernel.org>,
	"b.zolnierkie" <b.zolnierkie@samsung.com>,
	penguin-kernel <penguin-kernel@i-love.sakura.ne.jp>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Matthew Wilcox <willy@infradead.org>,
	"george.kennedy" <george.kennedy@oracle.com>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	tzimmermann <tzimmermann@suse.de>, sam <sam@ravnborg.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

- avoid top-posting, see https://git-send-email.io/top-posting.html
- use plain text email, html replies get dropped by many mailing lists.

The information from your reply should be part of the patch description when
you send a patch, see
https://www.kernel.org/doc/html/v4.17/process/submitting-patches.html


> [  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

  parent reply	other threads:[~2021-05-20  7:49 UTC|newest]

Thread overview: 6+ 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 12:00 ` songqiang
2021-05-19 12:16 ` Matthew Wilcox
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]
2021-05-20  7:48       ` 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=CAK8P3a2Pt+e3fbfWxJru7O-Np9u2u-_cVZqd5xBejLSraFYALQ@mail.gmail.com \
    --to=arnd@arndb.de \
    --cc=b.zolnierkie@samsung.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=george.kennedy@oracle.com \
    --cc=jgg@ziepe.ca \
    --cc=linux-fbdev@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=penguin-kernel@i-love.sakura.ne.jp \
    --cc=sam@ravnborg.org \
    --cc=songqiang@uniontech.com \
    --cc=tzimmermann@suse.de \
    --cc=willy@infradead.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.