Hi Geoffrey,
On Thu, 2025-03-13 at 17:43 +1030, Geoffrey D. Bennett wrote:
> On Thu, Mar 13, 2025 at 02:43:09AM +0100, Benedikt Ziemons wrote:
> > On Tue, 2025-03-11 at 21:53 -0400, Luiz Augusto von Dentz wrote:
> > > Hi Chris, Sean, Hao,
> > >
> > > On Mon, Mar 10, 2025 at 5:24 PM Geraldo Nascimento
> > > <geraldogabriel@xxxxxxxxx> wrote:
> > > >
> > > > On Sun, Mar 09, 2025 at 06:02:11AM +1030, Geoffrey D. Bennett
> > > > wrote:
> > > > > This series (choose 1 of the 2 patches) addresses an issue
> > > > > where
> > > > > the
> > > > > MT7922 Bluetooth controller reset added in commit
> > > > > ccfc8948d7e4
> > > > > ("Bluetooth: btusb: mediatek: reset the controller before
> > > > > downloading
> > > > > the fw") is causing Focusrite USB audio devices to fail to
> > > > > initialise
> > > > > when connected during boot on kernels 6.11 and newer.
> > > > >
> > > > > Reported by three users here:
> > > > > https://github.com/geoffreybennett/linux-fcp/issues/24
> > > > >
> > > > > Two users confirmed they have an MT7922.
> > > > >
> > > > > I'm providing two possible solutions as I note there was a
> > > > > similar
> > > > > change made in commit a7208610761a ("Bluetooth: btmtk: Remove
> > > > > resetting mt7921 before downloading the fw"), so I'm not sure
> > > > > if
> > > > > the
> > > > > reset should be reverted for the MT7925 as well as the
> > > > > MT7922.
> > > > >
> > > > > Option 1: Revert the problematic reset behaviour entirely
> > > > > (MT7922
> > > > > +
> > > > > MT7925)
> > > > >
> > > > > Option 2: Remove the reset only for the MT7922
> > > > >
> > > > > Geoffrey D. Bennett (2):
> > > > >
> > > > > [PATCH 1/2] Revert "Bluetooth: btusb: mediatek: reset the
> > > > > controller
> > > > > before downloading the fw"
> > > > >
> > > > > [PATCH 2/2] Bluetooth: btmtk: Remove resetting mt7922
> > > > > before
> > > > > downloading the fw
> > > > >
> > > > > --
> > > > > 2.45.0
> > > > >
> > > > >
> > > >
> > > > Hi Geoffrey,
> > > >
> > > > I understand there's no apparent nexus of causality here.
> > > >
> > > > However if three different users suddenly reported the same
> > > > problem
> > > > and
> > > > the fix fixes it, we should take the report seriously and back
> > > > down
> > > > on the problematic commit until we figure for sure what the
> > > > heck is
> > > > going on.
> > > >
> > > > My bet is this is bona fide bug in the USB subsystem, but
> > > > either
> > > > I'm not
> > > > looking hard enough or I'm looking into the wrong places,
> > > > because
> > > > there's no way I can see in which way USB bluetooth driver from
> > > > MediaTek could cause clock detection to fail.
> > > >
> > > > No point in pressing this harder, but yeah, take the reports
> > > > more
> > > > than
> > > > seriously, because if we don't understand in which way our own
> > > > (Linux)
> > > > code could be causing this, at least we should take cautionary
> > > > measures.
> > > >
> > > > In that sense, putting Takashi Iwai and Greg KH to Cc: in a
> > > > modest
> > > > but
> > > > sincere belief that this issue is more than real, even though
> > > > it
> > > > looks
> > > > like anticipated April 1st. Takashi can help with his expertise
> > > > in
> > > > clock
> > > > detection and Greg could help pinpoint if this is indeed
> > > > madness in
> > > > the
> > > > USB subsystem.
> > > >
> > > > Hope you and them don't mind the escalation :)
> > >
> > > Do you guys have any idea what could be possibly going on here?
> > > There
> > > really seems something is not right if one driver affects the
> > > other,
> > > especially if the devices are not actually related in any way.
> > >
> > >
> >
> > Hello everyone,
> >
> > I did the kernel bisection on this issue and tested Geoffrey's
> > patches
> > since I own the affected combination of hardware and can reliably
> > reproduce the issue.
> >
> > I was now able to capture both the sound device initialization
> > failure
> > and the successful initialization from initramfs using the usbmon
> > module. One difference that is immediately noticeable is the amount
> > of
> > URB_CONTROL data that is sent to the mediatek btusb device and a
> > considerable slow-down of the boot process (around 16s difference).
> >
> > Following is some more information about the timing and other
> > related
> > messages from the kernel message log. The first excerpt is from an
> > unpatched kernel 6.14.0-rc5:
> >
> > [ 59.987242] lunar kernel: usb 1-2: new high-speed USB device
> > number 2 using xhci_hcd
> > [ 59.987975] lunar kernel: usb 1-2: New USB device found,
> > idVendor=1235, idProduct=8212, bcdDevice= 6.45
> > [ 59.988048] lunar kernel: usb 1-2: New USB device strings:
> > Mfr=1, Product=3, SerialNumber=2
> > [ 59.988121] lunar kernel: usb 1-2: Product: Scarlett 4i4 USB
> > [ 59.988197] lunar kernel: usb 1-2: Manufacturer: Focusrite
> > [ 60.571193] lunar kernel: mt7921e 0000:0a:00.0: enabling device
> > (0000 -> 0002)
> > [ 60.571314] lunar kernel: mt7921e 0000:0a:00.0: ASIC revision:
> > 79220010
> > [ 60.571501] lunar kernel: usbcore: registered new interface
> > driver btusb
> > [ 60.571513] lunar kernel: mt7921e 0000:0a:00.0: HW/SW Version:
> > 0x8a108a10, Build Time: 20241106163228a
> > [ 60.571627] lunar kernel: mt7921e 0000:0a:00.0: WM Firmware
> > Version: ____000000, Build Time: 20241106163310
> > [ 60.616673] lunar kernel: Bluetooth: hci0: HW/SW Version:
> > 0x008a008a, Build Time: 20241106163512
> > [ 64.549017] lunar kernel: mt7921e 0000:0a:00.0 wlp10s0: renamed
> > from wlan0
> > [ 70.700407] lunar kernel: usb 1-2:
> > parse_audio_format_rates_v2v3(): unable to retrieve number of
> > sample rates (clock 41)
> > [ 81.264360] lunar kernel: usb 1-2:
> > parse_audio_format_rates_v2v3(): unable to retrieve number of
> > sample rates (clock 41)
> > [ 81.264611] lunar kernel: usb 1-2: Focusrite Scarlett Gen 3
> > Mixer Driver enabled (pid=0x8212); report any issues to
> > https://github.com/geoffreybennett/scarlett-gen2/issues
> > [ 81.264782] lunar kernel: usb 1-2: Error initialising Scarlett
> > Gen 3 Mixer Driver: -71
> > [ 81.264903] lunar kernel: snd-usb-audio 1-2:1.0: probe with
> > driver snd-usb-audio failed with error -71
> > [ 81.265040] lunar kernel: usb 1-2: Quirk or no altset; falling
> > back to MIDI 1.0
> > [ 81.400030] lunar kernel: Bluetooth: hci0: Device setup in
> > 20435397 usecs
> > [ 81.400114] lunar kernel: Bluetooth: hci0: HCI Enhanced Setup
> > Synchronous Connection command is advertised, but not supported.
> > [ 81.680052] lunar kernel: Bluetooth: hci0: AOSP extensions
> > version v1.00
> > [ 81.680170] lunar kernel: Bluetooth: hci0: AOSP quality report
> > is supported
> > [ 87.373353] lunar kernel: usbcore: registered new interface
> > driver snd-usb-audio
> >
> >
> > The following second excerpt is from the same kernel version with
> > Geoffrey's second patch applied:
> >
> > [ 139.603887] lunar kernel: usb 1-2: new high-speed USB device
> > number 2 using xhci_hcd
> > [ 139.604524] lunar kernel: usb 1-2: New USB device found,
> > idVendor=1235, idProduct=8212, bcdDevice= 6.45
> > [ 139.604598] lunar kernel: usb 1-2: New USB device strings:
> > Mfr=1, Product=3, SerialNumber=2
> > [ 139.604672] lunar kernel: usb 1-2: Product: Scarlett 4i4 USB
> > [ 139.604744] lunar kernel: usb 1-2: Manufacturer: Focusrite
> > [ 140.192488] lunar kernel: usbcore: registered new interface
> > driver btusb
> > [ 140.192501] lunar kernel: mt7921e 0000:0a:00.0: enabling device
> > (0000 -> 0002)
> > [ 140.192627] lunar kernel: Bluetooth: hci0: HW/SW Version:
> > 0x008a008a, Build Time: 20241106163512
> > [ 140.192639] lunar kernel: mt7921e 0000:0a:00.0: ASIC revision:
> > 79220010
> > [ 140.192753] lunar kernel: mt7921e 0000:0a:00.0: HW/SW Version:
> > 0x8a108a10, Build Time: 20241106163228a
> > [ 140.192866] lunar kernel: mt7921e 0000:0a:00.0: WM Firmware
> > Version: ____000000, Build Time: 20241106163310
> > [ 140.240011] lunar kernel: Bluetooth: hci0: Device setup in
> > 188119 usecs
> > [ 140.240048] lunar kernel: Bluetooth: hci0: HCI Enhanced Setup
> > Synchronous Connection command is advertised, but not supported.
> > [ 140.513341] lunar kernel: Bluetooth: hci0: AOSP extensions
> > version v1.00
> > [ 140.513379] lunar kernel: Bluetooth: hci0: AOSP quality report
> > is supported
> > [ 144.115475] lunar kernel: mt7921e 0000:0a:00.0 wlp10s0: renamed
> > from wlan0
> > [ 144.115747] lunar kernel: usb 1-2: Focusrite Scarlett Gen 3
> > Mixer Driver enabled (pid=0x8212); report any issues to
> > https://github.com/geoffreybennett/scarlett-gen2/issues
> > [ 144.115857] lunar kernel: usb 1-2: Firmware version 1605
> > [ 144.115954] lunar kernel: usb 1-2: Quirk or no altset; falling
> > back to MIDI 1.0
> > [ 147.843340] lunar kernel: usbcore: registered new interface
> > driver snd-usb-audio
> >
> >
> > Comparing the USB captures from the hub, filtered to just the first
> > few
> > messages of the audio device yield the following exchanges. Again,
> > first the broken case:
> >
> > No. Time Source Destination
> > Protocol Length Info
> > 7 0.011098 host 1.2.0
> > USB 64 GET DESCRIPTOR Request DEVICE
> > 8 0.015218 1.2.0 host
> > USB 82 GET DESCRIPTOR Response DEVICE
> > 9 0.015272 host 1.2.0
> > USB 64 GET DESCRIPTOR Request CONFIGURATION
> > 10 0.017966 1.2.0 host
> > USB 73 GET DESCRIPTOR Response CONFIGURATION
> > 11 0.018020 host 1.2.0
> > USB 64 GET DESCRIPTOR Request CONFIGURATION
> > 12 0.025965 1.2.0 host
> > USB 425 GET DESCRIPTOR Response CONFIGURATION
> > 23 2.482241 host 1.2.0
> > USB 64 GET DESCRIPTOR Request STRING
> > 24 2.484931 1.2.0 host
> > USB 98 GET DESCRIPTOR Response STRING
> > 25 2.484939 host 1.2.0
> > USB 64 GET DESCRIPTOR Request STRING
> > 26 2.487916 1.2.0 host
> > USB 84 GET DESCRIPTOR Response STRING
> > 27 2.487941 host 1.2.0
> > USBAUDIO 65 SET CUR CX_CLOCK_SELECTOR_CONTROL request
> > 2047 7.661154 1.2.0 host
> > USBAUDIO 64 SET CUR CX_CLOCK_SELECTOR_CONTROL status
> > 2048 7.661197 host 1.2.0
> > USBAUDIO 64 GET RANGE CS_SAM_FREQ_CONTROL request
> > 4097 12.781553 1.2.0 host
> > USBAUDIO 64 GET RANGE CS_SAM_FREQ_CONTROL[Malformed Packet]
> >
> >
> > The first discrepancy can be found in the URB status field of
> > packet
> > no. 2047 (vs. 74 below) which is -2: No such file or directory (-
> > ENOENT).
> > In the second (following) case where the sound device initializes
> > okay,
> > the URB status of the similar packet is Success (0) instead:
> >
> > No. Time Source Destination
> > Protocol Length Info
> > 7 0.011565 host 1.2.0
> > USB 64 GET DESCRIPTOR Request DEVICE
> > 8 0.015471 1.2.0 host
> > USB 82 GET DESCRIPTOR Response DEVICE
> > 9 0.015523 host 1.2.0
> > USB 64 GET DESCRIPTOR Request CONFIGURATION
> > 10 0.018477 1.2.0 host
> > USB 73 GET DESCRIPTOR Response CONFIGURATION
> > 11 0.018537 host 1.2.0
> > USB 64 GET DESCRIPTOR Request CONFIGURATION
> > 12 0.026331 1.2.0 host
> > USB 425 GET DESCRIPTOR Response CONFIGURATION
> > 23 4.168190 host 1.2.0
> > USB 64 GET DESCRIPTOR Request STRING
> > 24 4.171031 1.2.0 host
> > USB 98 GET DESCRIPTOR Response STRING
> > 25 4.171040 host 1.2.0
> > USB 64 GET DESCRIPTOR Request STRING
> > 26 4.174021 1.2.0 host
> > USB 84 GET DESCRIPTOR Response STRING
> > 27 4.174041 host 1.2.0
> > USBAUDIO 65 SET CUR CX_CLOCK_SELECTOR_CONTROL request
> > 74 4.476033 1.2.0 host
> > USBAUDIO 64 SET CUR CX_CLOCK_SELECTOR_CONTROL status
> > 75 4.476050 host 1.2.0
> > USBAUDIO 64 GET CUR CX_CLOCK_SELECTOR_CONTROL request
> > 76 4.479034 1.2.0 host
> > USBAUDIO 65 GET CUR CX_CLOCK_SELECTOR_CONTROL response
> > 77 4.479050 host 1.2.0
> > USBAUDIO 64 GET RANGE CS_SAM_FREQ_CONTROL request
> > 202 4.582043 1.2.0 host
> > USBAUDIO 66 GET RANGE CS_SAM_FREQ_CONTROL response
> >
> >
> > Please ask, if I should provide any more information or how and to
> > whom
> > I can provide the full USB captures.
> >
> > Thank you,
> > Ben
>
> Hi Ben,
>
> This bit sticks out to me:
>
> > [ 81.400030] lunar kernel: Bluetooth: hci0: Device setup in
> > 20435397 usecs
>
> 20 seconds to initialise bluetooth, vs. 188ms when not doing the
> reset:
>
> > [ 140.240011] lunar kernel: Bluetooth: hci0: Device setup in
> > 188119 usecs
>
> Does it still take 20 seconds when the Scarlett is not plugged in at
> boot time?
Yes, it still takes 20 seconds without the Scarlett plugged in. Here
are kernel messages about the mediatek device in this case:
[ 6.620016] lunar kernel: Bluetooth: Core ver 2.22
[ 6.666695] lunar kernel: NET: Registered PF_BLUETOOTH protocol family
[ 6.666756] lunar kernel: Bluetooth: HCI device and connection manager initialized
[ 6.666770] lunar kernel: Bluetooth: HCI socket layer initialized
[ 6.666784] lunar kernel: Bluetooth: L2CAP socket layer initialized
[ 6.666794] lunar kernel: Bluetooth: SCO socket layer initialized
[ 6.912392] lunar kernel: usbcore: registered new interface driver btusb
[ 6.912402] lunar kernel: mt7921e 0000:0a:00.0: enabling device (0000 -> 0002)
[ 6.912519] lunar kernel: mt7921e 0000:0a:00.0: ASIC revision: 79220010
[ 6.912627] lunar kernel: mt7921e 0000:0a:00.0: HW/SW Version: 0x8a108a10, Build Time: 20241106163228a
[ 6.912739] lunar kernel: mt7921e 0000:0a:00.0: WM Firmware Version: ____000000, Build Time: 20241106163310
[ 6.912847] lunar kernel: Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20241106163512
[ 8.010016] lunar kernel: mt7921e 0000:0a:00.0 wlp10s0: renamed from wlan0
[ 12.723353] lunar kernel: usbcore: registered new interface driver snd-usb-audio
[ 27.606693] lunar kernel: Bluetooth: hci0: Device setup in 20342576 usecs
[ 27.606748] lunar kernel: Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.
[ 27.883398] lunar kernel: Bluetooth: hci0: AOSP extensions version v1.00
[ 27.883466] lunar kernel: Bluetooth: hci0: AOSP quality report is supported
>
> I presume lsusb -t shows both devices on the same USB bus?
Yes, indeed, they are both on bus 1. For the captures I also made sure
that no other devices are on the same bus.
I also just tried connecting the Scarlett to a different USB bus and
cannot reproduce the original issue with this setup.
>
> Thanks,
> Geoffrey.
