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From: Hans Verkuil <hverkuil-qWit8jRvyhVmR6Xm/wNWPw@public.gmane.org>
To: Benoit Parrot <bparrot-l0cyMroinI0@public.gmane.org>,
	Mauro Carvalho Chehab
	<mchehab-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>
Cc: linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Hans Verkuil
	<hans.verkuil-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
Subject: Re: [Patch v5 1/2] media: v4l: ti-vpe: Add CAL v4l2 camera capture driver
Date: Mon, 14 Dec 2015 15:41:54 +0100	[thread overview]
Message-ID: <566ED532.6060308@xs4all.nl> (raw)
In-Reply-To: <20151211221633.GF1517-l0cyMroinI0@public.gmane.org>

On 12/11/2015 11:16 PM, Benoit Parrot wrote:
> Mauro Carvalho Chehab <mchehab-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org> wrote on Thu [2015-Dec-03 11:19:22 -0200]:
>>> +static int cal_enum_framesizes(struct file *file, void *fh,
>>> +			       struct v4l2_frmsizeenum *fsize)
>>> +{
>>> +	struct cal_ctx *ctx = video_drvdata(file);
>>> +	const struct cal_fmt *fmt;
>>> +	struct v4l2_subdev_frame_size_enum fse;
>>> +	int ret;
>>> +
>>> +	ctx_dbg(2, ctx, "%s\n", __func__);
>>
>> This s a general note: do you really need tracing-like debug macros
>> all around the code?
>>
>> You could easily check if the functions are called via trace.
> 
> True but that also mean to rebuild the kernel in order to
> get to it since function tracing is usually not enabled
> by default.
> 

You can enable debugging by doing:

echo 2 >/sys/class/video4linux/video0/dev_debug

See also: Documentation/video4linux/v4l2-framework.txt, section "video device
debugging" for more info.

That's always available and basically does what you want.

Regards,

	Hans

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WARNING: multiple messages have this Message-ID (diff)
From: Hans Verkuil <hverkuil@xs4all.nl>
To: Benoit Parrot <bparrot@ti.com>,
	Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: linux-media@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Hans Verkuil <hans.verkuil@cisco.com>
Subject: Re: [Patch v5 1/2] media: v4l: ti-vpe: Add CAL v4l2 camera capture driver
Date: Mon, 14 Dec 2015 15:41:54 +0100	[thread overview]
Message-ID: <566ED532.6060308@xs4all.nl> (raw)
In-Reply-To: <20151211221633.GF1517@ti.com>

On 12/11/2015 11:16 PM, Benoit Parrot wrote:
> Mauro Carvalho Chehab <mchehab@osg.samsung.com> wrote on Thu [2015-Dec-03 11:19:22 -0200]:
>>> +static int cal_enum_framesizes(struct file *file, void *fh,
>>> +			       struct v4l2_frmsizeenum *fsize)
>>> +{
>>> +	struct cal_ctx *ctx = video_drvdata(file);
>>> +	const struct cal_fmt *fmt;
>>> +	struct v4l2_subdev_frame_size_enum fse;
>>> +	int ret;
>>> +
>>> +	ctx_dbg(2, ctx, "%s\n", __func__);
>>
>> This s a general note: do you really need tracing-like debug macros
>> all around the code?
>>
>> You could easily check if the functions are called via trace.
> 
> True but that also mean to rebuild the kernel in order to
> get to it since function tracing is usually not enabled
> by default.
> 

You can enable debugging by doing:

echo 2 >/sys/class/video4linux/video0/dev_debug

See also: Documentation/video4linux/v4l2-framework.txt, section "video device
debugging" for more info.

That's always available and basically does what you want.

Regards,

	Hans


  parent reply	other threads:[~2015-12-14 14:41 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-18 20:47 [Patch v5 0/2] media: v4l: ti-vpe: Add CAL v4l2 camera capture driver Benoit Parrot
2015-11-18 20:47 ` Benoit Parrot
2015-11-18 20:47 ` [Patch v5 1/2] " Benoit Parrot
2015-11-18 20:47   ` Benoit Parrot
     [not found]   ` <1447879632-22635-2-git-send-email-bparrot-l0cyMroinI0@public.gmane.org>
2015-12-03 13:19     ` Mauro Carvalho Chehab
2015-12-03 13:19       ` Mauro Carvalho Chehab
     [not found]       ` <20151203111922.7b9bb226-+RedX5hVuTR+urZeOPWqwQ@public.gmane.org>
2015-12-11 22:16         ` Benoit Parrot
2015-12-11 22:16           ` Benoit Parrot
     [not found]           ` <20151211221633.GF1517-l0cyMroinI0@public.gmane.org>
2015-12-14 14:41             ` Hans Verkuil [this message]
2015-12-14 14:41               ` Hans Verkuil
2015-12-15 15:52           ` Mauro Carvalho Chehab
2015-12-15 15:52             ` Mauro Carvalho Chehab
2015-11-18 20:47 ` [Patch v5 2/2] media: v4l: ti-vpe: Document DRA72 CAL h/w module Benoit Parrot
2015-11-18 20:47   ` Benoit Parrot
2015-11-19 14:51   ` Rob Herring

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