From: "Seungchul Kim" <sc377.kim@samsung.com>
To: "'Hans Verkuil'" <hverkuil@xs4all.nl>, <mchehab@kernel.org>
Cc: <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<sc377.kim@samsung.com>
Subject: RE: [PATCH] media: v4l2-fh: define v4l2_fh struct regardless of condition
Date: Thu, 26 Mar 2020 18:13:53 +0900 [thread overview]
Message-ID: <001201d6034e$ded12830$9c737890$@samsung.com> (raw)
In-Reply-To: <3e38fc75-f555-7d91-2561-9c95f76694d1@xs4all.nl>
On 3/26/20 5:17 PM, Hans Verkuil wrote:
> On 3/26/20 3:30 AM, Seungchul Kim wrote:
> > On 3/25/20 5:54 PM, Hans Verkuil wrote:
> >> On 3/23/20 3:30 AM, Seungchul Kim wrote:
> >>> v4l2_fh struct define differently by CONFIG_V4L2_MEM2MEM_DEV.
> >>> If some vendors use CONFIG_V4L2_MEM2MEM_DEV by module, it can make
> >>> the mismatch of v4l2_fh sturct.
> >>>
> >>> By the mismatch, the following error occurs.
> >>> ===============================
> >>> [ 7.533506] v4l2_mem2mem: disagrees about version of symbol
> >> video_devdata
> >>> [ 7.533594] v4l2_mem2mem: Unknown symbol video_devdata (err -22)
> >>> [ 7.535319] v4l2_mem2mem: disagrees about version of symbol
> >>> v4l2_event_pending
> >>> [ 7.542532] v4l2_mem2mem: Unknown symbol v4l2_event_pending (err -22)
> >>> ===============================
> >>>
> >>> So v4l2_fh struct is modified to does not have dependency for
> >>> CONFIG_V4L2_MEM2MEM_DEV.
> >>>
> >>> Signed-off-by: Seungchul Kim <sc377.kim@samsung.com>
> >>> ---
> >>> include/media/v4l2-fh.h | 2 --
> >>> 1 file changed, 2 deletions(-)
> >>>
> >>> diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h index
> >>> 53b4dbb..b5b3e00 100644
> >>> --- a/include/media/v4l2-fh.h
> >>> +++ b/include/media/v4l2-fh.h
> >>> @@ -53,9 +53,7 @@ struct v4l2_fh {
> >>> unsigned int navailable;
> >>> u32 sequence;
> >>>
> >>> -#if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
> >>> struct v4l2_m2m_ctx *m2m_ctx;
> >>> -#endif
> >>
> >> This is a good change, but please also remove the same #if from
> >> v4l2_ioctl_get_lock() in drivers/media/v4l2-core/v4l2-ioctl.c. That
> >> is now no longer needed there either and without removing that those
> >> vendor drivers would be using the wrong lock.
> >>
> >> Regards,
> >>
> >> Hans
> >
> > Thank you for your comment. I worried about the same thing with you.
> > But vfh->m2m_ctx on v4l2_ioctl_get_lock() is always null without
> > CONFIG_V4L2_MEM2MEM_DEV, because m2m_ctx of v4l2-fh is initialized
> > only in v4l2_mem2mem.c.
> > Therefore it doesn't have a problem using an wrong lock regardless of
> > modification, so I did not fix it.
>
> It is: if your out-of-tree driver sets CONFIG_V4L2_MEM2MEM_DEV, then I
> assume it will set vfh->m2m_ctx, and so the v4l2 core should also return
> the right lock for that out-of-tree driver.
>
> But in any case, if m2m_ctx is always part of v4l2-fh.h, then that #if in
> v4l2-ioctl.c has become pointless and should be removed in any case.
>
> Regards,
>
> Hans
I agree with you, so I will update a patch, soon
next prev parent reply other threads:[~2020-03-26 9:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200323023045epcas2p12007502edd2a65efcccb00eb899d5532@epcas2p1.samsung.com>
2020-03-23 2:30 ` [PATCH] media: v4l2-fh: define v4l2_fh struct regardless of condition Seungchul Kim
2020-03-25 8:59 ` Greg KH
2020-03-25 16:54 ` Hans Verkuil
2020-03-26 2:30 ` Seungchul Kim
2020-03-26 8:16 ` Hans Verkuil
2020-03-26 9:13 ` Seungchul Kim [this message]
[not found] <CGME20200326091732epcas2p2be24b70dca0039b10b828e8b9102f6bf@epcas2p2.samsung.com>
2020-03-26 9:09 ` Seungchul Kim
[not found] <CGME20200320095559epcas2p2732ccb391573ba99e2dd08d6c50a18f2@epcas2p2.samsung.com>
2020-03-20 9:55 ` 김승철
[not found] <CGME20200320022445epcas2p40ea2f166aff45e67825b3e1a4e2308dd@epcas2p4.samsung.com>
2020-03-20 2:16 ` Seungchul Kim
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='001201d6034e$ded12830$9c737890$@samsung.com' \
--to=sc377.kim@samsung.com \
--cc=hverkuil@xs4all.nl \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=mchehab@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;
as well as URLs for NNTP newsgroup(s).