On Wed, 22 Apr 2009 20:05:40 +0200 "ext Menon, Nishanth" <nm@xxxxxx> wrote: > > Test tone is being presented by the user application, providing a > > 1Khz tone sampled at 44.1Khz. The data are S16_LE, right channel > > only. Left channel is quiet. The data seems to slip back and forth > > from left to right channel. This is reproducable and verified with > > a scope trace. > Is this slipping happening in middle of playback or between the tracks? > I recollect this issue from years back of OSS driver -> i2s is > configured as dual phase - mcbsp sends data on both edges, and if the > data write happen on the wrong edge for the wrong phase, we might get > mix up.. if I recollect right, configuration for mcbsp was done as a > single phase with the right edge as a trigger for transfer, the > transfer size was set as 32 bytes (both channels).. this essentially > guarentees that mcbsp will never mix up channels. > Thanks Menon! This is sounds a information we should try out. OMAP2420 in N810 is especially suffering from channel swapping between the tracks and I haven't found time to look any deeper :-( I know there is a fix for DaVinci (commit fb0ef645f2c546f8297b2fbf9b2b8fff4a7455e8) but I would like to find out are there any other or simpler way to fix it than mixing DMA and DAI setup. Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
