From: Lars-Peter Clausen <lars@metafoo.de>
To: Steve Longerbeam <slongerbeam@gmail.com>, linux-media@vger.kernel.org
Cc: Steve Longerbeam <steve_longerbeam@mentor.com>,
Hans Verkuil <hverkuil@xs4all.nl>
Subject: Re: [PATCH 02/11] Revert "[media] adv7180: fix broken standards handling"
Date: Thu, 7 Jul 2016 17:45:40 +0200 [thread overview]
Message-ID: <577E7924.9070301@metafoo.de> (raw)
In-Reply-To: <1467846004-12731-3-git-send-email-steve_longerbeam@mentor.com>
On 07/07/2016 12:59 AM, Steve Longerbeam wrote:
> Autodetect was likely broken only because access to the
> interrupt registers were broken, so there were no standard
> change interrupts. After fixing that, and reverting this,
> autodetect seems to work just fine on an i.mx6q SabreAuto.
>
> This reverts commit 937feeed3f0ae8a0389d5732f6db63dd912acd99.
The brokenness the commit refers to is conceptual not functional. The driver
simply implemented the API incorrect. A subdev driver is not allowed to
automatically switch the output format/resolution randomly. In the best case
this will confuse the receiver which is not prepared to receive the changed
resolution, in the worst case it will cause buffer overruns with hardware
that has no boundary checks. This is why this was removed from the driver.
The correct sequence is for the driver to generate a change notification and
then have userspace react to that notification by stopping the current
stream, query the new format/resolution, reconfigure the video pipeline for
the new format/resolution and re-start the stream.
next prev parent reply other threads:[~2016-07-07 15:45 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-06 22:59 [PATCH 00/11] adv7180 subdev fixes Steve Longerbeam
2016-07-06 22:59 ` [PATCH 01/11] media: adv7180: Fix broken interrupt register access Steve Longerbeam
2016-07-07 14:44 ` Tim Harvey
2016-07-07 15:37 ` Lars-Peter Clausen
2016-07-06 22:59 ` [PATCH 02/11] Revert "[media] adv7180: fix broken standards handling" Steve Longerbeam
2016-07-07 14:48 ` Tim Harvey
2016-07-07 15:45 ` Lars-Peter Clausen [this message]
2016-07-09 18:56 ` Steve Longerbeam
2016-07-06 22:59 ` [PATCH 03/11] media: adv7180: add power pin control Steve Longerbeam
2016-07-07 15:04 ` Tim Harvey
2016-07-07 15:35 ` Lars-Peter Clausen
2016-07-06 22:59 ` [PATCH 04/11] media: adv7180: implement g_parm Steve Longerbeam
2016-07-07 15:04 ` Tim Harvey
2016-07-06 22:59 ` [PATCH 05/11] media: adv7180: init chip with AD recommended register settings Steve Longerbeam
2016-07-07 15:23 ` Tim Harvey
2016-07-07 15:29 ` Lars-Peter Clausen
2016-07-06 22:59 ` [PATCH 06/11] media: adv7180: add bt.656-4 OF property Steve Longerbeam
2016-07-07 14:52 ` Lars-Peter Clausen
2016-07-09 18:59 ` Steve Longerbeam
2016-07-09 21:10 ` Steve Longerbeam
2016-07-09 21:36 ` Steve Longerbeam
2016-07-10 12:10 ` Lars-Peter Clausen
2016-07-10 12:55 ` Hans Verkuil
2016-07-10 14:17 ` Ian Arkver
2016-07-10 14:30 ` Hans Verkuil
2016-07-10 22:34 ` Steve Longerbeam
2016-07-11 7:06 ` Ian Arkver
2016-07-11 22:03 ` Steve Longerbeam
2016-07-12 10:25 ` Ian Arkver
2016-07-12 17:26 ` Steve Longerbeam
2016-07-06 23:00 ` [PATCH 07/11] media: adv7180: change mbus format to UYVY Steve Longerbeam
2016-07-07 15:18 ` Lars-Peter Clausen
2016-07-08 10:52 ` Niklas Söderlund
2016-07-07 15:25 ` Tim Harvey
2016-07-06 23:00 ` [PATCH 08/11] adv7180: send V4L2_EVENT_SOURCE_CHANGE on std change Steve Longerbeam
2016-07-07 15:27 ` Tim Harvey
2016-07-06 23:00 ` [PATCH 09/11] v4l: Add signal lock status to source change events Steve Longerbeam
2016-07-06 23:00 ` [PATCH 10/11] media: adv7180: enable lock/unlock interrupts Steve Longerbeam
2016-07-06 23:00 ` [PATCH 11/11] media: adv7180: fix field type Steve Longerbeam
2016-07-07 14:37 ` [PATCH 00/11] adv7180 subdev fixes Tim Harvey
2016-07-20 0:03 ` [PATCH v2 00/10] adv7180 subdev fixes, v2 Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 01/10] v4l: of: add "newavmode" property for Analog Devices codecs Steve Longerbeam
2016-07-20 7:37 ` Hans Verkuil
2016-07-20 17:14 ` Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 02/10] media: adv7180: Fix broken interrupt register access Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 03/10] media: adv7180: define more registers Steve Longerbeam
2016-07-20 8:54 ` Lars-Peter Clausen
2016-07-20 0:03 ` [PATCH v2 04/10] media: adv7180: add support for NEWAVMODE Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 05/10] media: adv7180: add power pin control Steve Longerbeam
2016-07-20 8:53 ` Lars-Peter Clausen
2016-07-20 0:03 ` [PATCH v2 06/10] media: adv7180: implement g_parm Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 07/10] media: adv7180: change mbus format to UYVY Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 08/10] v4l: Add signal lock status to source change events Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 09/10] media: adv7180: enable lock/unlock interrupts Steve Longerbeam
2016-07-20 0:03 ` [PATCH v2 10/10] media: adv7180: fix field type Steve Longerbeam
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