Commit 62abd092 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: usb-audio: Add implicit_fb module option 



A new module option, implicit_fb, is added to specify the driver
looking for the implicit feedback sync.  This can be useful for a
device that could be working better in the implicit feed back mode and
user wants to test it quickly.  When this works, we can add the quirk
entry easily.

Tested-by: default avatarKeith Milner <kamilner@superlative.org>
Tested-by: default avatarDylan Robinson <dylan_robinson@motu.com>
Link: https://lore.kernel.org/r/20201123085347.19667-40-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 83b7dcbc

Documentation/sound/alsa-configuration.rst

+5 −0
Original line number Diff line number Diff line
@@ -2227,6 +2227,11 @@ quirk_alias 
    Quirk alias list, pass strings like ``0123abcd:5678beef``, which

    applies the existing quirk for the device 5678:beef to a new

    device 0123:abcd.

implicit_fb

    Apply the generic implicit feedback sync mode.  When this is set

    and the playback stream sync mode is ASYNC, the driver tries to

    tie an adjacent ASYNC capture stream as the implicit feedback

    source.

use_vmalloc

    Use vmalloc() for allocations of the PCM buffers (default: yes).

    For architectures with non-coherent memory like ARM or MIPS, the

sound/usb/card.c

+4 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ static bool ignore_ctl_error; 
static bool autoclock = true;

static char *quirk_alias[SNDRV_CARDS];

static char *delayed_register[SNDRV_CARDS];

static bool implicit_fb[SNDRV_CARDS];



bool snd_usb_use_vmalloc = true;

bool snd_usb_skip_validation;
@@ -97,6 +98,8 @@ module_param_array(quirk_alias, charp, NULL, 0444); 
MODULE_PARM_DESC(quirk_alias, "Quirk aliases, e.g. 0123abcd:5678beef.");

module_param_array(delayed_register, charp, NULL, 0444);

MODULE_PARM_DESC(delayed_register, "Quirk for delayed registration, given by id:iface, e.g. 0123abcd:4.");

module_param_array(implicit_fb, bool, NULL, 0444);

MODULE_PARM_DESC(implicit_fb, "Apply generic implicit feedback sync mode.");

module_param_named(use_vmalloc, snd_usb_use_vmalloc, bool, 0444);

MODULE_PARM_DESC(use_vmalloc, "Use vmalloc for PCM intermediate buffers (default: yes).");

module_param_named(skip_validation, snd_usb_skip_validation, bool, 0444);
@@ -596,6 +599,7 @@ static int snd_usb_audio_create(struct usb_interface *intf, 
	chip->dev = dev;

	chip->card = card;

	chip->setup = device_setup[idx];

	chip->generic_implicit_fb = implicit_fb[idx];

	chip->autoclock = autoclock;

	atomic_set(&chip->active, 1); /* avoid autopm during probing */

	atomic_set(&chip->usage_count, 0);

sound/usb/implicit.c

+4 −0
Original line number Diff line number Diff line
@@ -269,6 +269,10 @@ static int audioformat_implicit_fb_quirk(struct snd_usb_audio *chip, 
			return 1;

	}



	/* Try the generic implicit fb if available */

	if (chip->generic_implicit_fb)

		return add_generic_implicit_fb(chip, fmt, alts);



	/* No quirk */

	return 0;

}

sound/usb/usbaudio.h

+1 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ struct snd_usb_audio { 
	struct list_head mixer_list;	/* list of mixer interfaces */



	int setup;			/* from the 'device_setup' module param */

	bool generic_implicit_fb;	/* from the 'implicit_fb' module param */

	bool autoclock;			/* from the 'autoclock' module param */



	struct usb_host_interface *ctrl_intf;	/* the audio control interface */

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