Messages in this thread |  | | Date | Tue, 9 Oct 2001 11:01:18 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: Emu10k1 driver update |
| |
On Tue, 9 Oct 2001, Rui Sousa wrote: > > Attached a patch for the emu10k1 kernel driver against 2.4.11pre6.
Applied. However..
> Changes: > Mixer improvements. > Fixed a dead lock in emu10k1_volxxx_irqhandler.
The locking still looks _very_ suspicious. The code seems to lock at all the wrong places, leaving a lot of accesses completely outside any locking. In particular, look at how the code in emu10k1_set_oss_vol() (which was apparently the one involved in the irqhandler lockup) now does not protect the mixer_state thing in _any_ way.
In general it is a bug to leave locking to the low-level routines, in this case to "emu10k1_set_volume_gpr()". I realize that somebody went "Ugh, we should try to make the locking regions as small as possible", but the fact is, locks that are _too_ small are no better than no locks at all.
It may be that there is some good reason for why the mixer_state thing doesn't need a lock - I only gave the patch a quick see-though, but if so maybe a single line comment migth be appropriate.
Linus
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |