firewire: deadline for PHY config transmission

If the low-level driver failed to initialize a card properly without
noticing it, fw-core was blocked indefinitely when trying to send a
PHY config packet.  This hung up the events kernel thread, e.g. locked
up keyboard input.
https://bugzilla.redhat.com/show_bug.cgi?id=444694
https://bugzilla.redhat.com/show_bug.cgi?id=446763

This problem was introduced between 2.6.25 and 2.6.26-rc1 by commit
2a0a2590498be7b92e3e76409c9b8ee722e23c8f "firewire: wait until PHY
configuration packet was transmitted (fix bus reset loop)".

The solution is to wait with timeout.  I tested it with 7 different
working controllers and 1 non-working controller.  On the working ones,
the packet callback complete()s usually --- but not always --- before a
timeout of 10ms.  Hence I chose a safer timeout of 100ms.

On the few tests with the non-working controller ALi M5271, PHY config
packet transmission always timed out so far.  (Fw-ohci needs to be fixed
for this controller independently of this deadline fix.  Often the core
doesn't even attempt to send a phy config because not even self ID
reception works.)

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