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author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-06-18 18:20:45 +0200 |
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committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-06-19 00:12:35 +0200 |
commit | ae1e53557911d7e60a637b2400173add958aae94 (patch) | |
tree | eb0e731e5ac2afcb3e39abacd6942bec7b8b52cd /drivers/watchdog/at32ap700x_wdt.c | |
parent | firewire: fw-ohci: unify printk prefixes (diff) | |
download | linux-ae1e53557911d7e60a637b2400173add958aae94.tar.xz linux-ae1e53557911d7e60a637b2400173add958aae94.zip |
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>
Diffstat (limited to 'drivers/watchdog/at32ap700x_wdt.c')
0 files changed, 0 insertions, 0 deletions