Am 15.03.2012 11:42, schrieb Mauro Carvalho Chehab: > Em 14-03-2012 21:28, Rui Salvaterra escreveu: >> 2012/3/14 Ezequiel García <elezegarcia@xxxxxxxxx>: >>> Hi, >>> >>> 2012/3/14 Rui Salvaterra <rsalvaterra@xxxxxxxxx>: >>>> Hi, Ezequiel. Thanks a lot for your reply. >>>> I'm attaching a copy of my full dmesg, its a bit hard to spot exactly >>>> where all modules are loaded (since the boot sequence became >>>> asynchronous). >>> Indeed. >>> >>>> >>>> Sure, no problem at all. I booted with em28xx disable_ir=1 and got the >>>> same result. Additionally: >>>> >>>> rui@wilykat:~$ lsmod | grep ir >>>> ir_lirc_codec 12901 0 >>>> lirc_dev 19204 1 ir_lirc_codec >>>> ir_mce_kbd_decoder 12724 0 >>>> ir_sanyo_decoder 12513 0 >>>> ir_sony_decoder 12510 0 >>>> ir_jvc_decoder 12507 0 >>>> ir_rc6_decoder 12507 0 >>>> ir_rc5_decoder 12507 0 >>>> ir_nec_decoder 12507 0 >>>> rc_core 26373 9 >>>> ir_lirc_codec,ir_mce_kbd_decoder,ir_sanyo_decoder,ir_sony_decoder,ir_jvc_decoder,ir_rc6_decoder,em28xx,ir_rc5_decoder,ir_nec_decoder >>>> rui@wilykat:~$ >>> Mmmm... >>> Are you completely sure that em28xx driver is triggering the load of >>> the ir related modules? >> I'm positive, the LIRC modules aren't loaded at all if I boot with the >> webcam disconnected. As soon as I plug it into an USB port, em28xx and >> LIRC are loaded. >> >>> Perhaps you could disable the module (blacklist, or compile out the >>> module, or erase em28xx.ko to make sure) >>> so you can see that effectively em28xx doesn't load and the rest of >>> the modules doesn't load either, >>> do you follow my line of reasoning? >> Ok, I did some more testing, here's what I found out. If I blacklist >> em28xx, no modules are loaded. Afterwards, I allowed em28xx to load >> and appended >> >> blacklist rc_core >> blacklist ir_lirc_codec >> blacklist lirc_dev >> blacklist ir_mce_kbd_decoder >> blacklist ir_sanyo_decoder >> blacklist ir_sony_decoder >> blacklist ir_jvc_decoder >> blacklist ir_rc6_decoder >> blacklist ir_rc5_decoder >> blacklist ir_nec_decoder >> >> to /etc/modprobe.d/blacklist.conf (basically blacklisted all LIRC >> stuff), but it also didn't work. And I still have em28xx disable_ir=1. > The em28xx module requires IR support from rc_core, as most em28xx devices > support it. It can be compiled without IR support, but, as the em28xx-input > is not on a separate module, and it contains some calls to rc_core functions > like rc_register_device, modprobe will load rc_core, and rc_core will load > the decoders, including lirc_dev. > > Those modules are small and won't be running if all you have are the webcams. > The optimization to not load those modules is not big, so nobody had time > yet to do it. > > Anyway, if you want to fix it, there are two possible approaches: > > 1) change rc_core to not load the IR decoders at load time, postponing it > to load only if a RC_DRIVER_IR_RAW device is registered via rc_register_device. > > A patch for it shouldn't be hard. All you need to do is to move ir_raw_init() > to rc_register_device() and add a logic there to call it for the first > raw device. > > With such patch, rc_core module will still be loaded. > > 2) change em28xx-input.c to be a separate module, called only when a device > has IR. It will need to have a logic similar to em28xx-dvb and em28xx-alsa > modules. > > It is not hard to write such patch, as most of the logic is already there, > but it is not as trivial as approach (1). > > It probably makes sense for both approaches (1) and (2), as not all boards > support "raw" devices. In the case of em28xx, there's no device using "raw" > mode, as the em28xx chips provide a hardware IR decoder. So, up to now, we > didn't find any em28xx device requiring a software decoder for IR. > > If you want to write patches for the above, they'll be welcome. > > I hope that helps. > > Regards, > Mauro > I would like to bring up the question, if it wouldn't make sense to move support for the em27xx/28xx webcams to a separate gspca-subdriver. I'm currently working on adding support for the VAD Laplace webcam (em2765 + OV2640) (http://linuxtv.org/wiki/index.php/VAD_Laplace). Lots of modifications to the em28xx driver would be necessary to support this device because of some significant differences: - supports only bulk transfers - uses proprietary I2C-writes - em25xx-eeprom - ov2640 sensor Lots of changes concerning the USB-interface probing, button handling, video controls, frame processing and more would be necessary, too. For reverse engineering purposes, I decided to write a gspca subdriver for this device (will send a patch for testing/discussion soon). I have no strong opinion about this, but I somehow feel that the em28xx driver gets bloated more and more... Regards, Frank Schäfer -- 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
