broken pcmcia_bus_match for dynids
linux at dominikbrodowski.net
Sat Jan 16 07:04:10 EST 2010
On Wed, Jan 13, 2010 at 01:42:05PM +0100, Jiri Slaby wrote:
> stanse found that when PCMCIA_DEV_ID_MATCH_FAKE_CIS is set in
> match_flags for a dynid, the pcmcia layer may deadlock.
> pcmcia_load_firmware in such case calls non-atomic operations
> (request_firmware, kzalloc(GFP_KERNEL)), while dynids.lock spinlock is held.
> Any ideas how to solve this? Any idea, why p_drv->dynids.lock is not a
> mutex instead?
Well, as dynid->id.cisfile is never set, it is still NULL, which means
pcmcia_load_firmware is left immediately, without calling the (blocking)
request_firmare(). So this actually isn't a problem, AFAICS.
Nonetheless, I'll prepare a patch to replace it with a mutex for 2.6.34.
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