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[Mark Haidekker <mhaidekk@xxxxxxxxx>]

** Attachment removed: "emumpu401.c"
   https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1328746/+attachment/4129882/+files/emumpu401.c

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https://bugs.launchpad.net/bugs/1328746

Title:
  Soundblaster Audigy front panel MIDI fails to initialize

Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  This bug has been around for a while. I have seen it in the forums
  circa 2007, and I have provided a solution in 2009. Since the modified
  code never found its way into the mainstream kernels, I am issuing the
  fix as a bug report.

  The bug concerns the Soundblaster Audigy cards with the emu10k1 chip
  in both i386 and amd64 architectures, in any kernel (standard, RT
  etc). They have on-board joystick MIDI. There is an optional front-
  panel module, which provides its own MIDI UART. Under Linux, the front
  MIDI does not work. People with dual-boot systems have reported that
  booting Windows first, then rebooting into Linux makes the UART
  function properly.

  The cause for the bug lies in the fact that the front panel MIDI is
  routed through a microcontroller (resides in the front panel module),
  and this microcontroller needs a defined reset signal once after
  power-up. Up to this point, the GPIO _levels_ are initialized
  correctly, but the reset _pulse_ is never issued. Essentially, the
  emu10k1 chip's GPIO2 needs to be pulled high for a brief interval.

  WORKAROUND: The bug can be fixed in the file linux-source-3.13.0/sound/pci/emu10k1/emumpu401.c in the function snd_emu10k1_audigy_midi(). The proposed patch follows right after the present initialization of the second UART (note the added variable "val" to store the GPIO bits):
  int snd_emu10k1_audigy_midi(struct snd_emu10k1 *emu)
  {
   struct snd_emu10k1_midi *midi;
   int err;
   unsigned int val;		/* Needed in GPOUT2 pulse initialization */

   midi = &emu->midi;
   if ((err = emu10k1_midi_init(emu, midi, 0, "Audigy MPU-401 (UART)")) < 0)
    return err;

   midi->tx_enable = INTE_MIDITXENABLE;
   midi->rx_enable = INTE_MIDIRXENABLE;
   midi->port = A_MUDATA1;
   midi->ipr_tx = IPR_MIDITRANSBUFEMPTY;
   midi->ipr_rx = IPR_MIDIRECVBUFEMPTY;
   midi->interrupt = snd_emu10k1_midi_interrupt;

   midi = &emu->midi2;
   if ((err = emu10k1_midi_init(emu, midi, 1, "Audigy MPU-401 #2")) < 0)
    return err;

   midi->tx_enable = INTE_A_MIDITXENABLE2;
   midi->rx_enable = INTE_A_MIDIRXENABLE2;
   midi->port = A_MUDATA2;
   midi->ipr_tx = IPR_A_MIDITRANSBUFEMPTY2;
   midi->ipr_rx = IPR_A_MIDIRECVBUFEMPTY2;
   midi->interrupt = snd_emu10k1_midi_interrupt2;

   /*** NEW CODE ***  Pulse reset line for the second UART */

   val = inl(emu->port + A_IOCFG);
   outl (val | A_IOCFG_GPOUT2, emu->port + A_IOCFG);
   udelay(10);		/* udelay is a bad kludge, but remember that this is called only once on startup */
   outl (val, emu->port + A_IOCFG);

   return 0;
  }

  I suspect that my use of udelay would make a real kernel hacker
  cringe, but the level of GPOUT2 needs to remain high for a few
  microseconds to provide a stable RESET signal.

  Anyway, this fixes the problem. I have applied the patch for pretty much every major upgrade of the kernel. It is sufficient to compile the module snd-emu10k1.ko and replace it in the module tree.
  ---
  ApportVersion: 2.14.1-0ubuntu3.2
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC2:  mhaidekk   2321 F.... pulseaudio
   /dev/snd/controlC1:  mhaidekk   2321 F.... pulseaudio
   /dev/snd/controlC0:  mhaidekk   2321 F.... pulseaudio
  CRDA: Error: [Errno 2] No such file or directory
  CurrentDesktop: KDE
  DistroRelease: Ubuntu 14.04
  EcryptfsInUse: Yes
  HibernationDevice: RESUME=UUID=b15a827a-7aa7-4add-a9b4-cb68262cfddd
  InstallationDate: Installed on 2013-12-31 (161 days ago)
  InstallationMedia: Kubuntu 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130822)
  IwConfig:
   eth1      no wireless extensions.

   lo        no wireless extensions.
  MachineType: BIOSTAR Group TA970
  NonfreeKernelModules: fglrx
  Package: linux (not installed)
  ProcFB: 0 VESA VGA
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-29-generic root=UUID=11a18cc0-0c2e-4ce8-9acd-44c5bb8820e2 ro
  ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
  RelatedPackageVersions:
   linux-restricted-modules-3.13.0-29-generic N/A
   linux-backports-modules-3.13.0-29-generic  N/A
   linux-firmware                             1.127.2
  RfKill:

  Tags:  trusty
  Uname: Linux 3.13.0-29-generic x86_64
  UpgradeStatus: Upgraded to trusty on 2014-06-07 (3 days ago)
  UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
  _MarkForUpload: True
  dmi.bios.date: 01/14/2013
  dmi.bios.vendor: American Megatrends Inc.
  dmi.bios.version: 4.6.4
  dmi.board.asset.tag: None
  dmi.board.name: TA970
  dmi.board.vendor: BIOSTAR Group
  dmi.chassis.asset.tag: None
  dmi.chassis.type: 3
  dmi.chassis.vendor: BIOSTAR Group
  dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr4.6.4:bd01/14/2013:svnBIOSTARGroup:pnTA970:pvr:rvnBIOSTARGroup:rnTA970:rvr:cvnBIOSTARGroup:ct3:cvr:
  dmi.product.name: TA970
  dmi.sys.vendor: BIOSTAR Group

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