[alsa-devel] [PATCH] ALSA: hda - using POS_FIX_LPIB on Broadwell HDMI Audio

[David Henningsson]

On 2014-05-08 09:58, Yang, Libin wrote:
> Hi Takashi,
>
> I tested the non-snoop mode. It's worse than snoop mode. Only noise can be heard if using non-snoop mode.
>
> I add the print in the function azx_position_ok(). The below is the dmesg:
> [  119.509631] <0>posbuf: 26368, lpib: 16320, wallclk: 2330325
> [  119.509674] snd_hda_intel 0000:00:03.0: IRQ timing workaround is activated for card #0. Suggest a bigger bdl_pos_adj.
> [  119.509683] <0>posbuf: 26368, lpib: 16332, wallclk: 2331659
> [  119.515467] <0>posbuf: 28224, lpib: 17444, wallclk: 2470504
> [  119.523460] <0>posbuf: 30592, lpib: 18976, wallclk: 2662403
> [  119.531431] <0>posbuf: 32128, lpib: 20508, wallclk: 2853751
> [  119.594932] snd_hda_intel 0000:00:03.0: Unstable LPIB (20416 >= 16384); disabling LPIB delay counting

This looks quite bad - is it not a hardware bug if LPIB > CBL (CBL 
should be 16384 in this case)?


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic