Thanks for your review. I'll waiting some reviews on other patches and resend a new version about it.
On 19/09/2025 04.21, Randy Dunlap wrote: > Hi-- > > On 9/18/25 2:24 AM, Cryolitia PukNgae via B4 Relay wrote: >> From: Cryolitia PukNgae <cryoli...@uniontech.com> >> >> Just briefly described about the option. >> >> Signed-off-by: Cryolitia PukNgae <cryoli...@uniontech.com> >> --- >> Documentation/sound/alsa-configuration.rst | 108 >> ++++++++++++++++++++--------- >> 1 file changed, 75 insertions(+), 33 deletions(-) >> >> diff --git a/Documentation/sound/alsa-configuration.rst >> b/Documentation/sound/alsa-configuration.rst >> index >> a2fb8ed251dd0294e7a62209ca15d5c32c6adfae..efffe3d534beeddcb6a47ac27a24defb6879f534 >> 100644 >> --- a/Documentation/sound/alsa-configuration.rst >> +++ b/Documentation/sound/alsa-configuration.rst >> @@ -2297,39 +2297,81 @@ skip_validation >> 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 could > > and may > or: and can > >> + be modified dynamically via sysfs. >> + The old usage accepts an array of integers, each of which apply quirk > > applies > >> + flags on the device in the order of probing. >> + e.g. ``quirk_flags=0x01,0x02`` applies get_sample_rate to the first > > E.g., > >> + 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 could be > > s/could/may/ > >> + specified as ``*`` to match any value. ``FLAGSx`` could be a set of > > s/could/may/ > >> + flags given by name, separated by ``|``, or a hexadecimal number >> + representing the bit flags. The available flag names are listed above. > > s/above/below/ ? > >> + An exclamation mark could be prefixed to a flag name to negate the flag. > s/could/may/ > >> + For example, >> ``1234:abcd:mixer_playback_min_mute|!ignore_ctl_error;*:*:0x01;`` > > What happens if the trailing (ending) ';' is omitted? This is where I found something strange when I was testing it myself. When I use `echo '*:*:mixer_playback_min_mute` > /sys/module/snd_usb_audio/parameters/quirk_flags`, the string received by the driver contains a lot of trailing spaces. I am not familiar with the kernel and don't know how to handle this situation. Simply adding a semicolon to the input will make the trailing spaces after the semicolon be ignored. > >> + 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 > > get vs Skip is a little confusing. This part is copied from Takashi Iwai[1]. It does a little confusing. >> + * 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 > > DSD-based > >> + * 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 closed interface during setting sample rate > > close > >> + * 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`` >> + Be similar to bit 24 but for capture streams > > Similar to > >> >> This module supports multiple devices, autoprobe and hotplugging. >> >> Are all of these quirks used on various devices or are some of these > just implemented just in case they are needed in the future?thanks. I believe in that all of them are used in quirk_flags_table in sound/usb/quirks.c 1. https://lore.kernel.org/all/20210729073855.19043-2-ti...@suse.de/ Best regards, Cryolitia
