diff options
Diffstat (limited to 'pkgs/kpatches/dragonfly/0001-ALSA-usb-audio-Add-a-volume-scale-quirk-for-AudioQue.patch')
| -rw-r--r-- | pkgs/kpatches/dragonfly/0001-ALSA-usb-audio-Add-a-volume-scale-quirk-for-AudioQue.patch | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/pkgs/kpatches/dragonfly/0001-ALSA-usb-audio-Add-a-volume-scale-quirk-for-AudioQue.patch b/pkgs/kpatches/dragonfly/0001-ALSA-usb-audio-Add-a-volume-scale-quirk-for-AudioQue.patch new file mode 100644 index 00000000..e04df9ed --- /dev/null +++ b/pkgs/kpatches/dragonfly/0001-ALSA-usb-audio-Add-a-volume-scale-quirk-for-AudioQue.patch @@ -0,0 +1,95 @@ +From 8ccfffa0584532d9a98646bc39ead0e2361a86a2 Mon Sep 17 00:00:00 2001 +From: Anssi Hannula <anssi.hannula@iki.fi> +Date: Sun, 16 Aug 2015 15:50:12 +0300 +Subject: [PATCH 1/3] ALSA: usb-audio: Add a volume scale quirk for AudioQuest + DragonFly + +AudioQuest DragonFly DAC reports a volume control range of 0..50 +(0x0000..0x0032) which in USB Audio means a range of 0 .. 0.2dB, which +is obviously incorrect and causes software using the dB information in +e.g. volume sliders to have a massive volume difference in 100..102% +range. + +The actual volume mapping seems to be neither linear volume nor linear +dB scale, but instead quite close to the cubic mapping e.g. alsamixer +uses, with a range of -53...0 dB. + +Add a quirk for DragonFly to use a custom dB mapping, based on my +measurements, using a 10-item range TLV (so it still fits in alsa-lib +MAX_TLV_RANGE_SIZE). + +Tested on AudioQuest DragonFly HW v1.2. The quirk is only applied if the +range is 0..50, so if this gets fixed/changed in later HW revisions it +will no longer be applied. + +Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi> +Cc: <stable@vger.kernel.org> +--- + sound/usb/mixer_quirks.c | 37 +++++++++++++++++++++++++++++++++++++ + 1 file changed, 37 insertions(+) + +diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c +index d3608c0..dee73fa 100644 +--- a/sound/usb/mixer_quirks.c ++++ b/sound/usb/mixer_quirks.c +@@ -37,6 +37,7 @@ + #include <sound/control.h> + #include <sound/hwdep.h> + #include <sound/info.h> ++#include <sound/tlv.h> + + #include "usbaudio.h" + #include "mixer.h" +@@ -1715,6 +1716,38 @@ static int snd_microii_controls_create(struct usb_mixer_interface *mixer) + return 0; + } + ++static void snd_dragonfly_quirk_db_scale(struct usb_mixer_interface *mixer) ++{ ++ struct usb_mixer_elem_list *list; ++ struct usb_mixer_elem_info *cval; ++ static const int unit_id = 7; ++ ++ /* approximation using 10 ranges based on output measurement on hw v1.2 */ ++ static const DECLARE_TLV_DB_RANGE(scale, ++ 0, 1, TLV_DB_MINMAX_ITEM(-5300, -4970), ++ 2, 5, TLV_DB_MINMAX_ITEM(-4710, -4160), ++ 6, 7, TLV_DB_MINMAX_ITEM(-3884, -3710), ++ 8, 14, TLV_DB_MINMAX_ITEM(-3443, -2560), ++ 15, 16, TLV_DB_MINMAX_ITEM(-2475, -2324), ++ 17, 19, TLV_DB_MINMAX_ITEM(-2228, -2031), ++ 20, 26, TLV_DB_MINMAX_ITEM(-1910, -1393), ++ 27, 31, TLV_DB_MINMAX_ITEM(-1322, -1032), ++ 32, 40, TLV_DB_MINMAX_ITEM(-968, -490), ++ 41, 50, TLV_DB_MINMAX_ITEM(-441, 0), ++ ); ++ ++ for (list = mixer->id_elems[unit_id]; list; list = list->next_id_elem) { ++ cval = (struct usb_mixer_elem_info *)list; ++ if (cval->control == UAC_FU_VOLUME && ++ cval->min == 0 && cval->max == 50) { ++ usb_audio_info(mixer->chip, "applying DragonFly dB scale quirk\n"); ++ list->kctl->tlv.p = scale; ++ list->kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ; ++ list->kctl->vd[0].access &= ~SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK; ++ } ++ } ++} ++ + int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer) + { + int err = 0; +@@ -1792,6 +1825,10 @@ int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer) + case USB_ID(0x1235, 0x800c): /* Focusrite Scarlett 18i20 */ + err = snd_scarlett_controls_create(mixer); + break; ++ ++ case USB_ID(0x21b4, 0x0081): /* AudioQuest DragonFly */ ++ snd_dragonfly_quirk_db_scale(mixer); ++ break; + } + + return err; +-- +2.5.3 + |