ALSA: doc: improved docs about quirk_flags in snd-usb-audio

    of the unit descriptor instead of a driver probe error, so that we

    can check its details.

quirk_flags

    Contains the bit flags for various device specific workarounds.

    Applied to the corresponding card index.

        * bit 0: Skip reading sample rate for devices

        * bit 1: Create Media Controller API entries

        * bit 2: Allow alignment on audio sub-slot at transfer

        * bit 3: Add length specifier to transfers

        * bit 4: Start playback stream at first in implement feedback mode

        * bit 5: Skip clock selector setup

        * bit 6: Ignore errors from clock source search

        * bit 7: Indicates ITF-USB DSD based DACs

        * bit 8: Add a delay of 20ms at each control message handling

        * bit 9: Add a delay of 1-2ms at each control message handling

        * bit 10: Add a delay of 5-6ms at each control message handling

        * bit 11: Add a delay of 50ms at each interface setup

        * bit 12: Perform sample rate validations at probe

        * bit 13: Disable runtime PM autosuspend

        * bit 14: Ignore errors for mixer access

        * bit 15: Support generic DSD raw U32_BE format

        * bit 16: Set up the interface at first like UAC1

        * bit 17: Apply the generic implicit feedback sync mode

        * bit 18: Don't apply implicit feedback sync mode

        * bit 19: Don't closed interface during setting sample rate

        * bit 20: Force an interface reset whenever stopping & restarting

          a stream

        * bit 21: Do not set PCM rate (frequency) when only one rate is

          available for the given endpoint.

        * bit 22: Set the fixed resolution 16 for Mic Capture Volume

        * bit 23: Set the fixed resolution 384 for Mic Capture Volume

        * bit 24: Set minimum volume control value as mute for devices

          where the lowest playback value represents muted state instead

          of minimum audible volume

        * bit 25: Be similar to bit 24 but for capture streams

    The option provides a refined and flexible control for applying quirk

    flags.  It allows to specify the quirk flags for each device, and can

    be modified dynamically via sysfs.

    The old usage accepts an array of integers, each of which applies quirk

    flags on the device in the order of probing.

    E.g., ``quirk_flags=0x01,0x02`` applies get_sample_rate to the first

    device, and share_media_device to the second device.

    The new usage accepts a string in the format of

    ``VID1:PID1:FLAGS1;VID2:PID2:FLAGS2;...``, where ``VIDx`` and ``PIDx``

    specify the device, and ``FLAGSx`` specify the flags to be applied.

    ``VIDx`` and ``PIDx`` are 4-digit hexadecimal numbers, and can be

    specified as ``*`` to match any value.  ``FLAGSx`` can be a set of

    flags given by name, separated by ``|``, or a hexadecimal number

    representing the bit flags.  The available flag names are listed below.

    An exclamation mark can be prefixed to a flag name to negate the flag.

    For example, ``1234:abcd:mixer_playback_min_mute|!ignore_ctl_error;*:*:0x01;``

    applies the ``mixer_playback_min_mute`` flag and clears the

    ``ignore_ctl_error`` flag for the device 1234:abcd, and applies the

    ``skip_sample_rate`` flag for all devices.

        * bit 0: ``get_sample_rate``

          Skip reading sample rate for devices

        * bit 1: ``share_media_device``

          Create Media Controller API entries

        * bit 2: ``align_transfer``

          Allow alignment on audio sub-slot at transfer

        * bit 3: ``tx_length``

          Add length specifier to transfers

        * bit 4: ``playback_first``

          Start playback stream at first in implement feedback mode

        * bit 5: ``skip_clock_selector``

          Skip clock selector setup

        * bit 6: ``ignore_clock_source``

          Ignore errors from clock source search

        * bit 7: ``itf_usb_dsd_dac``

          Indicates ITF-USB DSD-based DACs

        * bit 8: ``ctl_msg_delay``

          Add a delay of 20ms at each control message handling

        * bit 9: ``ctl_msg_delay_1m``

          Add a delay of 1-2ms at each control message handling

        * bit 10: ``ctl_msg_delay_5m``

          Add a delay of 5-6ms at each control message handling

        * bit 11: ``iface_delay``

          Add a delay of 50ms at each interface setup

        * bit 12: ``validate_rates``

          Perform sample rate validations at probe

        * bit 13: ``disable_autosuspend``

          Disable runtime PM autosuspend

        * bit 14: ``ignore_ctl_error``

          Ignore errors for mixer access

        * bit 15: ``dsd_raw``

          Support generic DSD raw U32_BE format

        * bit 16: ``set_iface_first``

          Set up the interface at first like UAC1

        * bit 17: ``generic_implicit_fb``

          Apply the generic implicit feedback sync mode

        * bit 18: ``skip_implicit_fb``

          Don't apply implicit feedback sync mode

        * bit 19: ``iface_skip_close``

          Don't close interface during setting sample rate

        * bit 20: ``force_iface_reset``

          Force an interface reset whenever stopping & restarting a stream

        * bit 21: ``fixed_rate``

          Do not set PCM rate (frequency) when only one rate is available

          for the given endpoint

        * bit 22: ``mic_res_16``

          Set the fixed resolution 16 for Mic Capture Volume

        * bit 23: ``mic_res_384``

          Set the fixed resolution 384 for Mic Capture Volume

        * bit 24: ``mixer_playback_min_mute``

          Set minimum volume control value as mute for devices where the

          lowest playback value represents muted state instead of minimum

          audible volume

        * bit 25: ``mixer_capture_min_mute``

          Similar to bit 24 but for capture streams

This module supports multiple devices, autoprobe and hotplugging.