On Sun, 2010-11-14 at 20:26 +1100, Vincent McIntyre wrote: > On 11/14/10, Andy Walls <awalls@xxxxxxxxxxxxxxxx> wrote: > > On Sun, 2010-11-14 at 09:08 +1100, Vincent McIntyre wrote: > > noop_llseek() is a newer kernl function that provided a trivial llseek() > > implmenetation for drivers that don't support llseek() but still want to > > provide a successful return code: > > > > http://lkml.org/lkml/2010/4/9/193 > > http://lkml.org/lkml/2010/4/9/184 > > > Thanks for explaining this. > First dumb question - (I'll try to minimise these) > > * Inspection of the patches new_build/backports shows all the patches > are to things in the v4l/ tree > * Yet the patch you pointed to is to fs/read_write.c and include/linux/fs.h > > So my question: should this function be implemented as a patch to > files outside the v4l/ tree I'm not sure, I haven't looked at the build system. I'm guessing no. The build system *should* be using the kernel include files from your distribution. Patching up fs.h in the git tree may not have any effect, and patching up fs/read_write.c in the git tree certainly won't have any effect. You also don't want to muck with your installed kernel files. > or as additional .c and .h files within the v4l top level. I guess the > latter would then need to be #included in a bunch of v4l files. I'm > mainly unsure of the convention here. 1. A simple, stupid patch would just a statically defined, non-inline noop_llseek() function in each affected .c file. In this particular case I'm not sure adding a special .h file, a new .c file, a way to build the new .c file, and a bunch of #include's is worth it. or 2. I suppose you could have a patch add a .h file that defined a non-inline static noop_llseek() function and just #include that where needed. or 3. You could just add #define noop_llseek NULL instead of a real function in either of 1 or 2 above. > I checked the mkrufky tree mentioned in README.patches but that didn't help. > I also checked the mercurial tree and could not find any backport of > noop_llseek, > but I may have missed something. > > The consumers of the function appear to be: > $ find v4l -exec grep -li noop_llseek {} \; > v4l/dvb_frontend.c > v4l/lirc_imon.c > v4l/lirc_dev.c > v4l/lirc_it87.c > v4l/imon.c > v4l/dvb_ca_en50221.c > v4l/dvb_net.c > v4l/dvbdev.c > v4l/lirc_sasem.c > v4l/av7110_av.c > v4l/av7110.c > v4l/av7110_ir.c > v4l/dst_ca.c > v4l/firedtv-ci.c Regards, Andy -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
