Commit 10389536742cefbedecb67a5b2906f155cf3a1c3
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firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder
Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check
whether the current IRM complies to 1394a-2000 or later. If not force a
compliant node (e.g. itself) to become IRM. This was implemented in the
older ieee1394 driver but not yet in firewire-core.
An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM
but neither 1394a-2000 IRM nor BM was now found to cause an
interoperability bug:
- Camcorder becomes root node when plugged in, hence gets IRM role.
- firewire-core successfully contends for BM role, proceeds to perform
gap count optimization and resets the bus.
- Sony camcorder ignores presence of a BM (against the spec, this is
a firmware bug), performs its idea of gap count optimization and
resets the bus.
- Preceding two steps are repeated endlessly, bus never settles,
regular I/O is practically impossible.
http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913
This is an interoperability regression from the old to the new drivers.
Fix it indirectly by adding the 1394a IRM check. The spec suggests
three and a half methods to determine 1394a compliance of a remote IRM;
we choose the method of testing the Config_ROM.Bus_Info.generation
field. This is data that firewire-core should have readily available at
this point, i.e. does not require extra I/O.
Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check)
Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25)
Tested-by: H. S. <hs.samix@gmail.com>
Cc: <stable@kernel.org> # .32.x and newer
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Showing 1 changed file with 19 additions and 5 deletions Side-by-side Diff
drivers/firewire/core-card.c
| ... | ... | @@ -231,7 +231,7 @@ |
| 231 | 231 | static void fw_card_bm_work(struct work_struct *work) |
| 232 | 232 | { |
| 233 | 233 | struct fw_card *card = container_of(work, struct fw_card, work.work); |
| 234 | - struct fw_device *root_device; | |
| 234 | + struct fw_device *root_device, *irm_device; | |
| 235 | 235 | struct fw_node *root_node; |
| 236 | 236 | unsigned long flags; |
| 237 | 237 | int root_id, new_root_id, irm_id, local_id; |
| ... | ... | @@ -239,6 +239,7 @@ |
| 239 | 239 | bool do_reset = false; |
| 240 | 240 | bool root_device_is_running; |
| 241 | 241 | bool root_device_is_cmc; |
| 242 | + bool irm_is_1394_1995_only; | |
| 242 | 243 | |
| 243 | 244 | spin_lock_irqsave(&card->lock, flags); |
| 244 | 245 | |
| 245 | 246 | |
| ... | ... | @@ -248,12 +249,18 @@ |
| 248 | 249 | } |
| 249 | 250 | |
| 250 | 251 | generation = card->generation; |
| 252 | + | |
| 251 | 253 | root_node = card->root_node; |
| 252 | 254 | fw_node_get(root_node); |
| 253 | 255 | root_device = root_node->data; |
| 254 | 256 | root_device_is_running = root_device && |
| 255 | 257 | atomic_read(&root_device->state) == FW_DEVICE_RUNNING; |
| 256 | 258 | root_device_is_cmc = root_device && root_device->cmc; |
| 259 | + | |
| 260 | + irm_device = card->irm_node->data; | |
| 261 | + irm_is_1394_1995_only = irm_device && irm_device->config_rom && | |
| 262 | + (irm_device->config_rom[2] & 0x000000f0) == 0; | |
| 263 | + | |
| 257 | 264 | root_id = root_node->node_id; |
| 258 | 265 | irm_id = card->irm_node->node_id; |
| 259 | 266 | local_id = card->local_node->node_id; |
| 260 | 267 | |
| ... | ... | @@ -276,11 +283,18 @@ |
| 276 | 283 | |
| 277 | 284 | if (!card->irm_node->link_on) { |
| 278 | 285 | new_root_id = local_id; |
| 279 | - fw_notify("IRM has link off, making local node (%02x) root.\n", | |
| 280 | - new_root_id); | |
| 286 | + fw_notify("%s, making local node (%02x) root.\n", | |
| 287 | + "IRM has link off", new_root_id); | |
| 281 | 288 | goto pick_me; |
| 282 | 289 | } |
| 283 | 290 | |
| 291 | + if (irm_is_1394_1995_only) { | |
| 292 | + new_root_id = local_id; | |
| 293 | + fw_notify("%s, making local node (%02x) root.\n", | |
| 294 | + "IRM is not 1394a compliant", new_root_id); | |
| 295 | + goto pick_me; | |
| 296 | + } | |
| 297 | + | |
| 284 | 298 | card->bm_transaction_data[0] = cpu_to_be32(0x3f); |
| 285 | 299 | card->bm_transaction_data[1] = cpu_to_be32(local_id); |
| 286 | 300 | |
| ... | ... | @@ -316,8 +330,8 @@ |
| 316 | 330 | * root, and thus, IRM. |
| 317 | 331 | */ |
| 318 | 332 | new_root_id = local_id; |
| 319 | - fw_notify("BM lock failed, making local node (%02x) root.\n", | |
| 320 | - new_root_id); | |
| 333 | + fw_notify("%s, making local node (%02x) root.\n", | |
| 334 | + "BM lock failed", new_root_id); | |
| 321 | 335 | goto pick_me; |
| 322 | 336 | } |
| 323 | 337 | } else if (card->bm_generation != generation) { |