)]}'
{
  "commit": "10389536742cefbedecb67a5b2906f155cf3a1c3",
  "tree": "cf0dbc030578e267e7f9fe1349083c3af3090f19",
  "parents": [
    "67a3e12b05e055c0415c556a315a3d3eb637e29e"
  ],
  "author": {
    "name": "Stefan Richter",
    "email": "stefanr@s5r6.in-berlin.de",
    "time": "Sun May 30 19:43:52 2010 +0200"
  },
  "committer": {
    "name": "Stefan Richter",
    "email": "stefanr@s5r6.in-berlin.de",
    "time": "Wed Jun 02 19:48:13 2010 +0200"
  },
  "message": "firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder\n\nPer IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check\nwhether the current IRM complies to 1394a-2000 or later.  If not force a\ncompliant node (e.g. itself) to become IRM.  This was implemented in the\nolder ieee1394 driver but not yet in firewire-core.\n\nAn older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM\nbut neither 1394a-2000 IRM nor BM was now found to cause an\ninteroperability bug:\n  - Camcorder becomes root node when plugged in, hence gets IRM role.\n  - firewire-core successfully contends for BM role, proceeds to perform\n    gap count optimization and resets the bus.\n  - Sony camcorder ignores presence of a BM (against the spec, this is\n    a firmware bug), performs its idea of gap count optimization and\n    resets the bus.\n  - Preceding two steps are repeated endlessly, bus never settles,\n    regular I/O is practically impossible.\nhttp://thread.gmane.org/gmane.linux.kernel.firewire.user/3913\n\nThis is an interoperability regression from the old to the new drivers.\nFix it indirectly by adding the 1394a IRM check.  The spec suggests\nthree and a half methods to determine 1394a compliance of a remote IRM;\nwe choose the method of testing the Config_ROM.Bus_Info.generation\nfield.  This is data that firewire-core should have readily available at\nthis point, i.e. does not require extra I/O.\n\nReported-by: Clemens Ladisch \u003cclemens@ladisch.de\u003e (missing 1394a check)\nReported-by: H. S. \u003chs.samix@gmail.com\u003e (issue with Sony DCR-TRV25)\nTested-by: H. S. \u003chs.samix@gmail.com\u003e\n\nCc: \u003cstable@kernel.org\u003e # .32.x and newer\n\nSigned-off-by: Stefan Richter \u003cstefanr@s5r6.in-berlin.de\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "9dcb30466ec0a22a11092decb65474e7bdcc5191",
      "old_mode": 33188,
      "old_path": "drivers/firewire/core-card.c",
      "new_id": "371713ff02660e0c0ab08bf86a3d496f90a6e718",
      "new_mode": 33188,
      "new_path": "drivers/firewire/core-card.c"
    }
  ]
}