ieee1394: ignore nonzero Bus_Info_Block.max_rom, fetch config ROM in quadlets

It is already known that buggy firmwares exist which report a bogus
link_spd in their config ROM bus info block.  We now got the first
report of a bogus max_rom too (Freecom FireWire Hard Drive 1TB,
http://bugzilla.kernel.org/show_bug.cgi?id=12206).

I suspect other OSs only use quadlet reads to fetch the config ROM,
otherwise the firmware authors would have noticed their mistake.
Hence limit ieee1394's config ROM fetching routine to quadlets as the
safe minimum regardless of what the bus info block says.

This will potentially slow the bus reset handling by nodemgr somewhat
down.  But most existing devices support only quadlet reads anyway,
hence there will often be no actual difference to before this change.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 1 insertions, 6 deletions

diff --git a/drivers/ieee1394/csr1212.h b/drivers/ieee1394/csr1212.h
index 043039fc63ec..aced168f1be2 100644
--- a/drivers/ieee1394/csr1212.h
+++ b/drivers/ieee1394/csr1212.h
@@ -200,7 +200,7 @@ struct csr1212_bus_ops {
          * entries located in the Units Space.  Must return 0 on success
          * anything else indicates an error. */
         int (*bus_read) (struct csr1212_csr *csr, u64 addr,
-                         u16 length, void *buffer, void *private);
+                         void *buffer, void *private);
 
         /* This function is used by csr1212 to allocate a region in units space
          * in the event that Config ROM entries don't all fit in the predefined
@@ -211,11 +211,6 @@ struct csr1212_bus_ops {
         /* This function is used by csr1212 to release a region in units space
          * that is no longer needed. */
         void (*release_addr) (u64 addr, void *private);
-
-        /* This function is used by csr1212 to determine the max read request
-         * supported by a remote node when reading the ConfigROM space.  Must
-         * return 0, 1, or 2 per IEEE 1212.  */
-        int (*get_max_rom) (u32 *bus_info, void *private);
 };