On Sat, 2010-04-10 at 18:28 -0400, Mark Lord wrote: > On 15/03/10 07:51 AM, Andy Walls wrote: > > On Sun, 2010-03-14 at 22:48 -0400, Mark Lord wrote: > >> On 03/02/10 07:40, Andy Walls wrote: > .. > >> after updating to the tip of the v4l2-dvb git tree last week, > >> I've been hitting the "no audio" on analog recordings bug much more often. > >> > >> Digging through google, it appears this problem has been around as long > >> as the cx18 driver has existed, with no clear resolution. Lots of people > >> have reported it to you before, and nobody has found a silver bullet fix. > .. > > Here are all the potential problem areas I can think of: > > > > 1. A/V digitizer/decoder audio detection firmware load and init. (I've > > added firmware readback verification to try and head this off.) > > > > 2. A/V digitizer decoder audio microcontroller hard reset and "soft" > > reset sequencing. (I think the cx18 driver has this wrong ATM.) > > > > 3. APU load and init. (The double load is to fix a DTV TS stream bug on > > every other APU& CPU firmware load sequence. The APU_AI_RESET is to > > fix the audio bitrate problem on first capture after a double firmware > > load.) > > > > 4. AI1 Mux setting failing when switching between the internal A/V > > decoder's I2S output and the external I2S inputs. (I thought I had this > > fixed, but I don't have detailed register specs for that register - so > > maybe not.) > > > > 5. A/V decoder audio clock PLL stops operating due to being programmed > > out of range. (This was a problem for 32 ksps audio a while ago, but > > I'm pretty confident I have it fixed.) > > > > 6. A/V decoder analog frontend setup for SIF wrong?. (I fixed this due > > to a problen Helen Buus reported with cable TV.) > > > > I think #2 is the real problem. I just started to disassmble the > > digitizer firmware 2 nights ago to see if I could get some insight as to > > how to properly reset it. > > > > I've got a first WAG at fixing the resets of the audio microcontroller's > > resets at: > > > > http://linuxtv.org/hg/~awalls/cx18-audio > > > > If it doesn't work, change the CXADEC_AUDIO_SOFT_RESET register define > > from 0x810 to 0x9cc, although that may not work either. > .. > > Thanks for the troubleshooting and reporting. > .. > > Back at this again today, after a month away from it -- getting tired > of watching "Survivor" with closed-captioning instead of audio. :) > > I pulled your (Andy) repository today, and merged the cx18 audio reset > changes from it into today's tip from v4l-dvb. Patch attached for reference. > > So far, so good. I'll keep tabs on it over time, and see if the audio > is stable, or if it still fails once in a while. Hmmm. Darren's having problems (loss of video/black screen) with my patches under my cx18-audio repo, but I'm not quite convinced he doesn't have some other PCI bus problem either. Anyway, my plan now is this: 1. on cx18-av-core.c:input_change() a. set register 0x808 for audio autodetection b. restart the format detection loop c. set or reset a 1.5 second timeout 2. after the timer expires, if no audio standard was detected, a. force the audio standard by programming register 0x808 (e.g. BTSC for NTSC-M) b. restart the format detection loop so the micrcontroller will do the unmute when it detects audio Darren is in NTSC-M/BTSC land. What TV standard are you dealing with? 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
