[libcamera-devel,v2] libcamera: Add option to configure udev support

18794 diff mbox series

libcamera uses udev to support hotplug (and unplug) detection. This is
an optional feature, which gets selected automatically if udev is
available. Users may however want to build libcamera without hotplug
detection, even if udev is available on the system. Add a new feature
option to control udev support. The default value is auto, which retains
the existing behaviour.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v1:

- Add configuration summary for hotplug
---
 meson.build               | 1 +
 meson_options.txt         | 5 +++++
 src/libcamera/meson.build | 2 +-
 3 files changed, 7 insertions(+), 1 deletion(-)


base-commit: d06ed87d49ca3d734fd1c2f1409280abb499c625
prerequisite-patch-id: 03020483e75d365fa1661922fc66b2f16ea11a04

Hi Laurent,

On 7/6/23 10:00 AM, Laurent Pinchart via libcamera-devel wrote:
> libcamera uses udev to support hotplug (and unplug) detection. This is
> an optional feature, which gets selected automatically if udev is
> available. Users may however want to build libcamera without hotplug
> detection, even if udev is available on the system. Add a new feature
> option to control udev support. The default value is auto, which retains
> the existing behaviour.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>

> ---
> Changes since v1:
>
> - Add configuration summary for hotplug
> ---
>   meson.build               | 1 +
>   meson_options.txt         | 5 +++++
>   src/libcamera/meson.build | 2 +-
>   3 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/meson.build b/meson.build
> index 29777529a0d9..363de459e537 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -261,6 +261,7 @@ py_mod.find_installation('python3', modules : py_modules)
>   summary({
>               'Enabled pipelines': pipelines,
>               'Enabled IPA modules': enabled_ipa_names,
> +            'Hotplug support': libudev.found(),
>               'Tracing support': tracing_enabled,
>               'Android support': android_enabled,
>               'GStreamer support': gst_enabled,
> diff --git a/meson_options.txt b/meson_options.txt
> index 4405b401d7d3..fad928af4b62 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -66,6 +66,11 @@ option('tracing',
>           value : 'auto',
>           description : 'Enable tracing (based on lttng)')
>   
> +option('udev',
> +       type : 'feature',
> +       value : 'auto',
> +       description : 'Enable udev support for hotplug')
> +
>   option('v4l2',
>           type : 'boolean',
>           value : false,
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 38fbb41e7d6c..b24f82965764 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -76,7 +76,7 @@ libdl = null_dep
>   if not cc.has_function('dlopen')
>       libdl = cc.find_library('dl')
>   endif
> -libudev = dependency('libudev', required : false)
> +libudev = dependency('libudev', required : get_option('udev'))
>   libyaml = dependency('yaml-0.1', required : false)
>   
>   # Use one of gnutls or libcrypto (provided by OpenSSL), trying gnutls first.
>
> base-commit: d06ed87d49ca3d734fd1c2f1409280abb499c625
> prerequisite-patch-id: 03020483e75d365fa1661922fc66b2f16ea11a04

Quoting Laurent Pinchart via libcamera-devel (2023-07-06 09:00:58)
> libcamera uses udev to support hotplug (and unplug) detection. This is
> an optional feature, which gets selected automatically if udev is
> available. Users may however want to build libcamera without hotplug
> detection, even if udev is available on the system. Add a new feature
> option to control udev support. The default value is auto, which retains
> the existing behaviour.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> Changes since v1:
> 
> - Add configuration summary for hotplug
> ---
>  meson.build               | 1 +
>  meson_options.txt         | 5 +++++
>  src/libcamera/meson.build | 2 +-
>  3 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/meson.build b/meson.build
> index 29777529a0d9..363de459e537 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -261,6 +261,7 @@ py_mod.find_installation('python3', modules : py_modules)
>  summary({
>              'Enabled pipelines': pipelines,
>              'Enabled IPA modules': enabled_ipa_names,
> +            'Hotplug support': libudev.found(),

That's a bit different to others ... I guess there's no specific reason
to have a 'hotplug_enabled' flag so


Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

>              'Tracing support': tracing_enabled,
>              'Android support': android_enabled,
>              'GStreamer support': gst_enabled,
> diff --git a/meson_options.txt b/meson_options.txt
> index 4405b401d7d3..fad928af4b62 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -66,6 +66,11 @@ option('tracing',
>          value : 'auto',
>          description : 'Enable tracing (based on lttng)')
>  
> +option('udev',
> +       type : 'feature',
> +       value : 'auto',
> +       description : 'Enable udev support for hotplug')
> +
>  option('v4l2',
>          type : 'boolean',
>          value : false,
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 38fbb41e7d6c..b24f82965764 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -76,7 +76,7 @@ libdl = null_dep
>  if not cc.has_function('dlopen')
>      libdl = cc.find_library('dl')
>  endif
> -libudev = dependency('libudev', required : false)
> +libudev = dependency('libudev', required : get_option('udev'))
>  libyaml = dependency('yaml-0.1', required : false)
>  
>  # Use one of gnutls or libcrypto (provided by OpenSSL), trying gnutls first.
> 
> base-commit: d06ed87d49ca3d734fd1c2f1409280abb499c625
> prerequisite-patch-id: 03020483e75d365fa1661922fc66b2f16ea11a04
> -- 
> Regards,
> 
> Laurent Pinchart
>