On 07/28/2016 08:54 PM, Stefan Sauer wrote: > On 07/28/2016 01:27 PM, Clemens Ladisch wrote: >> Stefan Sauer wrote: >>> Another weir issue is that once the usb connection is established, >>> playing the synth from its own knobs and keys is super sluggish (e.g. a >>> key release is recognized with a multi-second delay). >> Apparently, the firmware waits for the PC to read the MIDI messages. >> Which the Linux driver does not do until a MIDI port is actually opened, >> in order to save a little bit of power. Oh well, I'll have to change >> this back. > If you can point me to the change I can locally test if that fixes it. I > just rebuilt my kernel and locally applied > http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/?id=ae7cc709f2ec11b49fc31b20cd8c943794ae9576 > which is only in Takashis branch, but not in the mainline. It does not > seem seem to have any visiible effect though. > Am I right to assume that the quirks-table.h ends up in snd-usb-audio.ko > ? Because I only updated this mod. My bad, you removed the quirks entry in http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8e5ced83dd1c3090c96c4e0614703f0f2a5ba2f4 So they don't seems to be needed anymore. > Any idea what I could try to figure out why the incomming audio is silent? >>> One detail is that when connecting the synth to usb I get several >>> "[159320.243035] usb 4-1.5: Unable to change format on ep #84: already >>> in use" messages in syslog. >> This is another driver bug. The exact cause is not known, and nobody >> has fixed it yet due to lack of time. > This is from ./sound/usb/endpoint.c:811: > I am really just guessing, but could this be related to that these > devices run both an audio and a midi interface on the same usb connection? This sees to be causing the silent input audio, endpoint 84 might be the audio-in Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 1 bNumEndpoints 1 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 2 bInterfaceProtocol 1 iInterface 0 ** UNRECOGNIZED: 07 24 01 07 00 01 00 ** UNRECOGNIZED: 0b 24 02 01 02 04 18 01 44 ac 00 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 37 Transfer Type Isochronous Synch Type Asynchronous Usage Type Implicit feedback Data wMaxPacketSize 0x0070 1x 112 bytes bInterval 1 Stefan > > Stefan >> >> Regards, >> Clemens > > > > ------------------------------------------------------------------------------ > _______________________________________________ > Alsa-user mailing list > Alsa-user@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/alsa-user ------------------------------------------------------------------------------ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
