Greg Erskine wrote: > Good news, SamS, fingers crossed, but I would like to know why you need > to change your buffer and I don't :confused:
LOL. Greg, you really don't want to go there! I can give one example where disk io, (especially on the Pi compared to other "similar" ARM hardware), whereby using a lower speed (class) sdcard, requires increasing buffer to a USB DAC, (doubling the settings I posted earlier), to stay glitch free. May not be quite so much of an issue with pico, but on my full-blown Fedora images which are writing to SDCARD a lot more, (systemd journald and app logging while developing), and CPU spending a lot of time in wait, waiting for IO to complete, it's most definitely an issue, and without increasing buffer, a train wreck. I'd expect to get booed out of the thread, on the basis it's about a software image that runs on Pi's, so I'll be careful how I put this, but it wouldn't be too hard for me to suggest that anyone wanting to end up with what I'd classify as a HQ audio music player, based on a USB platform (and regardless of the DAC it's feeding), should stay the hell away from the Pi. Gordon's FIQ work and P33M's complete re-write of the USB driver, don't completely paper over the cracks. Other people have dropped breadcrumbs...... Take the P33M patch above. Here's a quote from P33M when he was discussing Pi handling of ISO transfers.... "To elaborate, support for USB1.1 Isochronous on Raspberry Pi has been troublesome due to limitations with the hardware on BCM2835. It's not a conventional USB host. In fact word from the original IP implementors is that it was never intended to be used in this fashion, so Raspberry Pi are basically "on their own" as far as support is concerned." The grief/quirkiness with ARM USB implementations has recently seen me walking away from ARM (and using Bay Trail Intel NUC's) as the head unit for a high-end USB DAC I've been working on. (Another project that may or may not see the commercial light of day.) ------------------------------------------------------------------------ JackOfAll's Profile: http://forums.slimdevices.com/member.php?userid=3069 View this thread: http://forums.slimdevices.com/showthread.php?t=97803 _______________________________________________ unix mailing list unix@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/unix
