On Friday 08 May 2009 17:23:22 ext Jarkko Nikula wrote: > On Fri, 8 May 2009 16:55:01 +0300 > > Jarkko Nikula <jhnikula@xxxxxxxxx> wrote: > > Would it be possible that pop is not caused by the HS output but > > inside the chip, like from DAC? > > Seems to be not the case. Pops are there even if I put msleep(250) > before and after playing with the HS. > > A digital scope would definitely help here to see are there ramp and is > the coupling configuration correct. OK I got the scope hooked up. Startup sequence on HS looks fine: TWL4030_VMID_EN TWL4030_RAMP_EN HS gain restore. On the shutdown sequence part I have the following: ~TWL4030_RAMP_EN msleep(30) ~TWL4030_VMID_EN HS gain mute When the RAMP_DELAY = 0 (27/20/14 ms) the voltage on the HSOL line gradually ramps down. If I set the RAMP_DELAY = 1 (55/40/27 ms) the voltage on HSOL line starts to gradually ramp down, but close to the end there is a clear cut (voltage jumps to 0, after around 30ms from the start of the ramp down). If I further increase the RAMP_DELAY, the cut happens at the same time, but it falls from even higher voltage to 0. I think the solution for now is to fix the RAMP_DELAY to 0 (27/20/14 ms), and add the delay for the shutdown case. Also I have tried gradually decrease the volume on the HS output. It does not seams to be working on the twl4030 codec: when the HSL_GAIN, HSR_GAIN is set to 0 it effectively cuts the output (HSOL line drops to zero -> 'tuck' can be heard) Mark: what do you think, is it acceptable to add a maximum of 27ms delay to the hsol_event:SND_SOC_DAPM_POST_PMD event? -- Péter _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
