kernel.git/drivers/usb/gadget/function/f_uac2.c, branch linux-5.14.y

usb: gadget: f_uac2: fixed EP-IN wMaxPacketSize

2021-10-13T07:41:49Z

commit 0560c9c552c1815e7b480bc11fd785fefc82bb27 upstream. Async feedback patches broke enumeration on Windows 10 previously fixed by commit 789ea77310f0 ("usb: gadget: f_uac2: always increase endpoint max_packet_size by one audio slot"). While the existing calculation for EP OUT capture for async mode yields size+1 frame due to uac2_opts->fb_max > 0, playback side lost the +1 feature. Therefore the +1 frame addition must be re-introduced for playback. Win10 enumerates the device only when both EP IN and EP OUT max packet sizes are (at least) +1 frame. Fixes: e89bb4288378 ("usb: gadget: u_audio: add real feedback implementation") Cc: stable Tested-by: Henrik Enquist Tested-by: Jack Pham Signed-off-by: Pavel Hofman Link: https://lore.kernel.org/r/20210924080027.5362-1-pavel.hofman@ivitera.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: Populate SS descriptors' wBytesPerInterval

2021-09-30T08:13:08Z

commit f0e8a206a2a53a919e1709c654cb65d519f7befb upstream. For Isochronous endpoints, the SS companion descriptor's wBytesPerInterval field is required to reserve bus time in order to transmit the required payload during the service interval. If left at 0, the UAC2 function is unable to transact data on its playback or capture endpoints in SuperSpeed mode. Since f_uac2 currently does not support any bursting this value can be exactly equal to the calculated wMaxPacketSize. Tested with Windows 10 as a host. Fixes: f8cb3d556be3 ("usb: f_uac2: adds support for SS and SSP") Cc: stable Signed-off-by: Jack Pham Link: https://lore.kernel.org/r/20210909174811.12534-3-jackp@codeaurora.org [jackp: Backport to 5.14 with minor conflict resolution] Signed-off-by: Jack Pham Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: Add missing companion descriptor for feedback EP

2021-09-30T08:13:08Z

commit 595091a1426a3b2625dad322f69fe569dc9d8943 upstream. The f_uac2 function fails to enumerate when connected in SuperSpeed due to the feedback endpoint missing the companion descriptor. Add a new ss_epin_fback_desc_comp descriptor and append it behind the ss_epin_fback_desc both in the static definition of the ss_audio_desc structure as well as its dynamic construction in setup_headers(). Fixes: 24f779dac8f3 ("usb: gadget: f_uac2/u_audio: add feedback endpoint support") Cc: stable Signed-off-by: Jack Pham Link: https://lore.kernel.org/r/20210909174811.12534-2-jackp@codeaurora.org [jackp: Backport to 5.14 with minor conflict resolution] Signed-off-by: Jack Pham Signed-off-by: Greg Kroah-Hartman

usb: gadget: u_audio: add real feedback implementation

2021-06-09T09:26:49Z

This adds interface between userspace and feedback endpoint to report real feedback frequency to the Host. Current implementation adds new userspace interface ALSA mixer control "Capture Pitch 1000000" (similar to aloop driver's "PCM Rate Shift 100000" mixer control) Value in PPM is chosen to have correction value agnostic of the actual HW rate, which the application is not necessarily dealing with, while still retaining a good enough precision to allow smooth clock correction on the playback side, if necessary. Similar to sound/usb/endpoint.c, a slow down is allowed up to 25%. This has no impact on the required bandwidth. Speedup correction has an impact on the bandwidth reserved for the isochronous endpoint. The default allowed speedup is 500ppm. This seems to be more than enough but, if necessary, this is configurable through a module parameter. The reserved bandwidth is rounded up to the next packet size. Usage of this new control is easy to implement in existing userspace tools like alsaloop from alsa-utils. Signed-off-by: Ruslan Bilovol Signed-off-by: Jerome Brunet Link: https://lore.kernel.org/r/20210603220104.1216001-4-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: add adaptive sync support for capture

2021-06-09T09:26:49Z

Current f_uac2 USB OUT (aka 'capture') synchronization implements 'ASYNC' scenario which means USB Gadget has it's own freerunning clock and can update Host about real clock frequency through feedback endpoint so Host can align number of samples sent to the USB gadget to prevent overruns/underruns In case if Gadget can has no it's internal clock and can consume audio samples at any rate (for example, on the Gadget side someone records audio directly to a file, or audio samples are played through an external DAC as soon as they arrive), UAC2 spec suggests 'ADAPTIVE' synchronization type. Change UAC2 driver to make it configurable through additional 'c_sync' configfs file. Default remains 'asynchronous' with possibility to switch it to 'adaptive' Signed-off-by: Ruslan Bilovol Signed-off-by: Jerome Brunet Link: https://lore.kernel.org/r/20210603220104.1216001-3-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2/u_audio: add feedback endpoint support

2021-06-09T09:26:49Z

As per USB and UAC2 specs, asynchronous audio sink endpoint requires explicit synchronization mechanism (Isochronous Feedback Endpoint) Implement feedback companion endpoint for ISO OUT endpoint This patch adds all required infrastructure and USB requests handling for feedback endpoint. Syncrhonization itself is still dummy (feedback ep always reports 'nomimal frequency' e.g. no adjustement is needed). This satisfies hosts that require feedback endpoint (like Win10) and poll it periodically Actual synchronization mechanism should be implemented separately Signed-off-by: Ruslan Bilovol Signed-off-by: Jerome Brunet Link: https://lore.kernel.org/r/20210603220104.1216001-2-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: validate input parameters

2021-03-23T11:54:56Z

Currently user can configure UAC2 function with parameters that violate UAC2 spec or are not supported by UAC2 gadget implementation. This can lead to incorrect behavior if such gadget is connected to the host - like enumeration failure or other issues depending on host's UAC2 driver implementation, bringing user to a long hours of debugging the issue. Instead of silently accept these parameters, throw an error if they are not valid. Signed-off-by: Ruslan Bilovol Link: https://lore.kernel.org/r/1614599375-8803-4-git-send-email-ruslan.bilovol@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: f_uac2: adds support for SS and SSP

2021-03-23T11:51:24Z

Patch adds support of SS and SSP speed. Signed-off-by: Pawel Laszczak Link: https://lore.kernel.org/r/20210310105216.38202-1-pawell@gli-login.cadence.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: always increase endpoint max_packet_size by one audio slot

2021-03-10T08:36:12Z

As per UAC2 Audio Data Formats spec (2.3.1.1 USB Packets), if the sampling rate is a constant, the allowable variation of number of audio slots per virtual frame is +/- 1 audio slot. It means that endpoint should be able to accept/send +1 audio slot. Previous endpoint max_packet_size calculation code was adding sometimes +1 audio slot due to DIV_ROUND_UP behaviour which was rounding up to closest integer. However this doesn't work if the numbers are divisible. It had no any impact with Linux hosts which ignore this issue, but in case of more strict Windows it caused rejected enumeration Thus always add +1 audio slot to endpoint's max packet size Fixes: 913e4a90b6f9 ("usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth") Cc: Peter Chen Cc: #v4.3+ Signed-off-by: Ruslan Bilovol Link: https://lore.kernel.org/r/1614599375-8803-2-git-send-email-ruslan.bilovol@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: reset wMaxPacketSize

2020-12-28T14:56:22Z

With commit 913e4a90b6f9 ("usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth") wMaxPacketSize is computed dynamically but the value is never reset. Because of this, the actual maximum packet size can only decrease each time the audio gadget is instantiated. Reset the endpoint maximum packet size and mark wMaxPacketSize as dynamic to solve the problem. Fixes: 913e4a90b6f9 ("usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth") Signed-off-by: Jerome Brunet Cc: stable Link: https://lore.kernel.org/r/20201221173531.215169-2-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman