[libcamera-devel] [PATCH] meson: detect kernel version

[scerveau]

Hi Kieran,

Thank you for your feedback.
I updated the message to be shorter and more explicit (I hope).

Concerning V4L2 message, yes that's the original issue I was facing :) 
Not understand what I neeed to do fix this error:

V4L2 API v4.15.18 too old, v5.0.0 or later

Maybe we should fix this message too :)

Stéphane.

On 11/6/20 11:09, Kieran Bingham wrote:
> Hi Stéphane,
> 
> On 11/06/2020 09:43, Stéphane Cerveau wrote:
>> Add kernel version detection to warn user
>> that only >= 5.0.0 V4L API are supported in
>> libcamera.
>>
>> Signed-off-by: Stéphane Cerveau <scerveau at collabora.com>
>> ---
>>   meson.build | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/meson.build b/meson.build
>> index e898782..a72fef6 100644
>> --- a/meson.build
>> +++ b/meson.build
>> @@ -105,6 +105,14 @@ if get_option('test')
>>       subdir('test')
>>   endif
>>   
>> +if not meson.is_cross_build()
>> +  kernel_version_req = '>= 5.0.0'
>> +  kernel_version = run_command('uname', '-r').stdout()
> 
>> meson.build:112: WARNING: V4L2 API version 5.4.0-33-generic
>>   is too old, >= 5.8.0 is required, consider to upgrade your kernel version to use libcamera
> 
> This needs a .strip() at the end to remove the new lines:
> 
>> +  if not kernel_version.version_compare(kernel_version_req)
>> +    warning('V4L2 API version @0@ is too old, @1@ is required, consider to upgrade your kernel version to use
> libcamera'.format(kernel_version, kernel_version_req))
> 
> That line is really long, can it be reduced? At the very least, the
> .format() can move to a new line I believe.
> 
> 
> Grammatically I think this should be :
>   "consider upgrading your"
> rather than
>   "consider to upgrade"
> 
> but that's longer ;-(
> 
> 
> "WARNING: V4L2 API version 5.4.0-33-generic"
> 
> That's not really the V4L2 API version (I mean I guess it is) but it's
> the Linux-kernel version...
> 
> So I wouldn't reference the V4L2 API there ...
> 
> 
>> +  endif
>> +endif
>> +
>>   # Create a symlink from the build root to the source root. This is used when
>>   # running libcamera from the build directory to locate resources in the source
>>   # directory (such as IPA configuration files).
>>
>