Re: [PATCH] (new for ppa and imm) Re: [PATCH] Re: Patch to fix lockup on ppa insert

From: John Cavan (johncavan@home.com)
Date: Sat Nov 18 2000 - 17:10:24 EST


Tim Waugh wrote:
>
> On Thu, Nov 16, 2000 at 09:50:40PM -0500, John Cavan wrote:
>
> > [...] This patch unlocks, allows the lowlevel driver to do it's
> > probes, and then relocks. It could probably be more granular in the
> > parport_pc code, but my own home tests show it to be working fine.
>
> Is that safe?

I'm not sure. I know why it causes the NMI lockup, but I'm not enough of
an expert to sort it out. I've got a pretty good feel for the Zip
driver, but not the parport or scsi code yet, so I don't know how safe
it is. The new scsi error stuff does mention that drivers must
spinunlock/spinlock if it enables interrupts.

> Also, what bit of the parport code is tripping over the lock?
> Request_module or something?

During the init phase of the parport_pc module it probes and enables the
IRQ(s) of the parallel port, but the scsi layer has them locked.

> A nicer fix would probably be to use parport_register_driver, but
> that's likely to be too big a change right now.

I agree and it's recommended in the parport code. Now if I can get
enough time, I will take a stab at it, but nobody should be relying on
me for it. :o)

John
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Thu Nov 23 2000 - 21:00:16 EST