Re: [PATCH] media_build: fix module_*_driver redefined warnings

[Gianluca Gennari <gennarone@gmail.com>]

Il 09/04/2012 14:34, Mauro Carvalho Chehab ha scritto:
> Hi Gianluca,
> 
> Em 20-03-2012 11:10, Gianluca Gennari escreveu:
> 
> Please avoid adding more tests for an specific Kernel version here. There are
> two issues with checks like that:
> 
> 	1) this may break on some kernel-fix release that might backport the function.
> This is not very common, but there was some cases like that, in the USB subsystem;
> 
> 	2) this generally breaks compilation, after some time, if someone tries
> to compile it against a distribution-patched kernel, as the new code may be
> backported there.
> 
> That's said, if just doing an "#ifdef module_usb_driver" doesn't work because this
> is not a macro, you can add a simple check at this script:
> 	v4l/scripts/make_config_compat.pl 
> 
> like this one:
> 
> 	check_file_for_func("include/linux/delay.h", "usleep_range", "NEED_USLEEP_RANGE");
> 
> This function will seek for "usleep_range" at the delay.h header. If not found, it will
> add a #define NEED_USLEEP_RANGE at v4l/config-compat.h, that can be checked inside compat.h:
> 
> #ifdef NEED_USLEEP_RANGE
> #define usleep_range(min, max) msleep(min/1000)
> #endif
> 
> You can use the same kind of logic for module_usb_driver.
> 
> Regards,
> Mauro

Hi Mauro,
thanks for the explanation but Hans Verkuil already solved the issue
using the check_file_for_func method:

http://git.linuxtv.org/media_build.git/commit/2492bf186743a925db98694911649fa0e94003f5

Of course, I agree this is a much better solution.

Regards,
Gianluca