From: Shuah Khan <skhan@linuxfoundation.org>
To: Hans Verkuil <hverkuil@xs4all.nl>,
sakari.ailus@linux.intel.com, laurent.pinchart@ideasonboard.com,
dan.carpenter@oracle.com, mchehab@kernel.org
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
alsa-devel@alsa-project.org,
Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH] media: Fix Media Controller API config checks
Date: Tue, 15 Jun 2021 21:15:01 -0600 [thread overview]
Message-ID: <6b1bbc25-83fb-2c40-1dff-c2eb755a99cc@linuxfoundation.org> (raw)
In-Reply-To: <ee53183f-6c44-4ddb-a8b1-40d650772c73@linuxfoundation.org>
On 6/15/21 10:55 AM, Shuah Khan wrote:
> On 6/15/21 7:36 AM, Hans Verkuil wrote:
>> Hi Shuah,
>>
>> On 11/06/2021 03:58, Shuah Khan wrote:
>>> Smatch static checker warns that "mdev" can be null:
>>>
>>> sound/usb/media.c:287 snd_media_device_create()
>>> warn: 'mdev' can also be NULL
>>>
>>> If CONFIG_MEDIA_CONTROLLER is disabled, this file should not be included
>>> in the build.
>>>
>>> The below conditions in the sound/usb/Makefile are in place to ensure
>>> that
>>> media.c isn't included in the build.
>>>
>>> sound/usb/Makefile:
>>> snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
>>>
>>> select SND_USB_AUDIO_USE_MEDIA_CONTROLLER if MEDIA_CONTROLLER &&
>>> (MEDIA_SUPPORT=y || MEDIA_SUPPORT=SND_USB_AUDIO)
>>>
>>> The following config check in include/media/media-dev-allocator.h is
>>> in place to enable the API only when CONFIG_MEDIA_CONTROLLER and
>>> CONFIG_USB are enabled.
>>>
>>> #if defined(CONFIG_MEDIA_CONTROLLER) && defined(CONFIG_USB)
>>>
>>> This check doesn't work as intended when CONFIG_USB=m. When
>>> CONFIG_USB=m,
>>> CONFIG_USB_MODULE is defined and CONFIG_USB is not. The above config
>>> check
>>> doesn't catch that CONFIG_USB is defined as a module and disables the
>>> API.
>>> This results in sound/usb enabling Media Controller specific ALSA driver
>>> code, while Media disables the Media Controller API.
>>>
>>> Fix the problem requires two changes:
>>>
>>> 1. Change the check to use IS_ENABLED to detect when CONFIG_USB is
>>> enabled
>>> as a module or static. Since CONFIG_MEDIA_CONTROLLER is a bool,
>>> leave
>>> the check unchanged to be consistent with drivers/media/Makefile.
>>>
>>> 2. Change the drivers/media/mc/Makefile to include mc-dev-allocator.o
>>> in mc-objs when CONFIG_USB is y or m.
>>
>> If I test this patch, then I get:
>>
>> drivers/media/mc/mc-dev-allocator.c:97:22: error: redefinition of
>> 'media_device_usb_allocate'
>> 97 | struct media_device *media_device_usb_allocate(struct
>> usb_device *udev,
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~
>> In file included from drivers/media/mc/mc-dev-allocator.c:24:
>> include/media/media-dev-allocator.h:55:36: note: previous definition
>> of 'media_device_usb_allocate' was here
>> 55 | static inline struct media_device *media_device_usb_allocate(
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/media/mc/mc-dev-allocator.c:119:6: error: redefinition of
>> 'media_device_delete'
>> 119 | void media_device_delete(struct media_device *mdev, const
>> char *module_name,
>> | ^~~~~~~~~~~~~~~~~~~
>> In file included from drivers/media/mc/mc-dev-allocator.c:24:
>> include/media/media-dev-allocator.h:59:20: note: previous definition
>> of 'media_device_delete' was here
>> 59 | static inline void media_device_delete(
>> | ^~~~~~~~~~~~~~~~~~~
>>
>> The .config has:
>>
>> # CONFIG_USB_SUPPORT is not set
>> CONFIG_MEDIA_CONTROLLER=y
>>
>
Hi Hans,
I don't know why I made the logic fancy and complex. Fixed now and
sending v2 shortly. I made sure all the combinations are tested now.
thanks,
-- Shuah
prev parent reply other threads:[~2021-06-16 3:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-11 1:58 [PATCH] media: Fix Media Controller API config checks Shuah Khan
2021-06-15 13:36 ` Hans Verkuil
2021-06-15 14:09 ` Shuah Khan
2021-06-15 16:55 ` Shuah Khan
2021-06-16 3:15 ` Shuah Khan [this message]
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