From 84d69e790f48ff2e8472a8cf602243e43683eaf0 Mon Sep 17 00:00:00 2001 From: Anssi Hannula Date: Thu, 24 Oct 2013 21:10:38 +0300 Subject: [PATCH] ALSA: hda - hdmi: Disable ramp-up/down for non-PCM on AMD codecs Recent AMD HDMI codecs (revision ID 3 and later, 0x100300 as reported by procfs codec#0) have a configurable ramp-up/down functionality. The documentation ( http://www.x.org/docs/AMD/AMD_HDA_verbs_v2.pdf ) specifies that 180 ("180/256 =~ 0.7") is recommended for PCM and 0 for non-PCM. Apply the recommended values according to provided S/PDIF AES0 settings since ramp-up/down does not make sense for non-PCM. v2: adapted to hdmi_ops infrastructure * More note from Anssi: actually, re-reading mails reveals that Olivier didn't find the expected difference with this setting, except for "maybe slightly slower startup with AES0=6" (i.e. value 0, which is unexpected). So maybe a) it makes too unnoticiable a difference, or b) only affects certain hardware (card and/or sink), or c) ramp-up/down is only triggered with the MUTE bit of ATI_VERB_SET_MULTICHANNEL_xx which is also rev3+ specific, but is not presently used by the driver, or something else. So there's a significant chance setting ramp rate is useless for us ATM, but probably does not do actual harm either. Signed-off-by: Anssi Hannula Tested-by: Olivier Langlois # v1 Signed-off-by: Takashi Iwai --- Reading git-format-patch failed