On Thu, Feb 15, 2007 at 04:37:16PM +0200, Teemu Suikki wrote: > > > .. Replying to myself.. The problem seems to be in kernel level after > > > all, I enabled ir_debug in budget-ci module and the same delay is there > > > as well, debug log appears at the same time as vdr reacts to the > > > keypress. > > > > This is a known driver problem: a link to a patch was posted a few weeks > > back which removes this delay. See: > > http://www.linuxtv.org/pipermail/vdr/2007-February/011994.html > > > > I've always had more success with a home-brew LIRC receiver on a serial > > port. > > I think I'll go for LIRC too.. :( I installed the above patch, it is > slightly better but not very much. But are you using the cx88 kernel module? My patch probably breaks all other drivers depending on ir-common.c or ir-funtions.c, as it is called in later 2.6 kernels. I'm talking about this patch, which I have been using since I made it: http://www.iki.fi/~msmakela/software/vdr/linux-2.6.15.2-cx88_input2.patch As far as I understand, the cx23882 features a 32-bit shift register for sampling the output of the infrared receiver and generates an interrupt after every 32 shifted bits. I don't know the shifting frequency, but let's assume that the shift register takes 6 samples of each time base T=16/9 ms. The duration of a whole RC5 frame is 64*T, or about 114 ms. The worst case delay of the shift register would then be something like 32*(T/6) = 9.5 ms. By Nyquist's sampling theorem, the absolute minimum sampling frequency would be 1/T (because the minimum pulse width in RC5 code is T/2). Thus, the maximum delay caused by the shift register would be 32*T = 57 ms. I don't think that you can notice that kind of delays, nor that you would get much smaller delays with LIRC. Marko
