> -----Original Message----- > From: Troy Kisky [mailto:troy.kisky@xxxxxxxxxxxxxxxxxxx] > Sent: Wednesday, November 18, 2009 12:39 AM > To: Aggarwal, Anuj > Cc: alsa-devel@xxxxxxxxxxxxxxxx; linux-omap@xxxxxxxxxxxxxxx > Subject: Re: Artifacts present in AIC23 capture for 48 KHz > sampling rate > > Aggarwal, Anuj wrote: > >> -----Original Message----- > >> From: Aggarwal, Anuj > >> Sent: Friday, November 06, 2009 6:28 PM > >> To: alsa-devel@xxxxxxxxxxxxxxxx; 'linux-omap@xxxxxxxxxxxxxxx' > >> Subject: Artifacts present in AIC23 capture for 48 KHz sampling rate > >> > >> Hi, > >> > >> I am observing artifacts (sharp spikes at fixed intervals) while > >> capturing audio on AM3517 EVM and AIC23 codec. They are present only > >> in one of the channels when I am capturing at 48 KHz. All other > >> sampling rates are working fine with the above said combination. > >> > >> I have also attached the screenshot taken with the help of Audacity > >> utility. Here, I tried recording silence but artifacts were observed > >> on one channel. > >> > >> Has anyone also observed the similar behavior with AIC23 codec? Any > >> hints on what could be the root cause? > > [Aggarwal, Anuj] On further debugging, I found that the function > > find_rate() in sound/soc/codecs/tlv320aic23.c is not returning > > the correct value for capture in 48KHz sample rate. In USB mode > > (MCLK=12MHz), for 48KHz, it returns 0x7D (CLKOUT=0, CLKIN=1, > > SR[3:0]=0xF, BOSR=1, Normal=1) whereas as per the AIC23B spec, > > 0x7D would be BOSR = 0, USB/NORMAL = 1, SR=0xff, div2 = 1 > > The bug is with sr_valid_mask, > > static const unsigned short sr_valid_mask[] = { > LOWER_GROUP|UPPER_GROUP, /* Normal, bosr - 0*/ > LOWER_GROUP|UPPER_GROUP, /* Normal, bosr - 1*/ > LOWER_GROUP, /* Usb, bosr - 0*/ > UPPER_GROUP, /* Usb, bosr - 1*/ > }; > > should be > > static const unsigned short sr_valid_mask[] = { > LOWER_GROUP|UPPER_GROUP, /* Normal, bosr - 0*/ > LOWER_GROUP, /* Usb, bosr - 0*/ > LOWER_GROUP|UPPER_GROUP, /* Normal, bosr - 1*/ > UPPER_GROUP, /* Usb, bosr - 1*/ > }; > > > Can you give this a try and let me know? [Aggarwal, Anuj] I tried this on AM3517 EVM + AIC23B; it works fine for me. But I have tested the fix only with a 12 MHz clock. Thanks for quickly fixing this. > > Thanks > Troy > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
