Re: + hpsa-use-msleep-instead-of-schedule_timeout.patch added to -mm tree

Andrew Morton
2009-12-08T22:44:28Z

On Tue, 08 Dec 2009 23:25:05 +0100
Jiri Slaby <jirislaby@gmail.com> wrote:

> On 12/08/2009 11:04 PM, akpm@linux-foundation.org wrote:
> > Subject: hpsa: use msleep() instead of schedule_timeout
> > From: Stephen M. Cameron <scameron@beardog.cce.hp.com>
> >
> > Use msleep() instead of schedule_timeout
>
> The patch does more than that and moreover in a wrong manner, see below.
>
> > @@ -3262,8 +3262,8 @@ static int hpsa_pci_init(struct ctlr_inf
> > if (!(readl(h->vaddr + SA5_DOORBELL) & CFGTBL_ChangeReq))
> > break;
> > /* delay and try again */
> > - set_current_state(TASK_INTERRUPTIBLE);
> > - schedule_timeout(10);
> > + set_current_state(TASK_UNINTERRUPTIBLE);
> > + msleep(10);
>
> Why do you change interruptible sleep to uninterruptible?

Stealth bugfix ;)

If the calling process (called "modprobe") has signal_pending()
(someone ^C'ed it) then the TASK_INTERRUPTIBLE sleep will be a no-op
and the driver will probably go and screw things up.

> And you
> intermix jiffies with msecs. Use schedule_timeout_interruptible(10).
>
> > @@ -3302,7 +3302,8 @@ static int __devinit hpsa_init_one(struc
> >
> > /* Some devices (notably the HP Smart Array 5i Controller)
> > need a little pause here */
> > - schedule_timeout_uninterruptible(HPSA_POST_RESET_PAUSE);
> > + set_current_state(TASK_UNINTERRUPTIBLE);
> > + msleep(HPSA_POST_RESET_PAUSE_MSECS);
>
> Hmm, setting the state is superfluous, as msleep does the job itself.

yup, I fixed those.

> > diff -puN drivers/scsi/hpsa.h~hpsa-use-msleep-instead-of-schedule_timeout drivers/scsi/hpsa.h
> > --- a/drivers/scsi/hpsa.h~hpsa-use-msleep-instead-of-schedule_timeout
> > +++ a/drivers/scsi/hpsa.h
> ...
> > @@ -139,7 +139,7 @@ struct ctlr_info {
> > #define HPSA_BOARD_READY_ITERATIONS \
> > ((HPSA_BOARD_READY_WAIT_SECS * 1000) / \
> > HPSA_BOARD_READY_POLL_INTERVAL_MSECS)
> > -#define HPSA_POST_RESET_PAUSE (30 * HZ)
> > +#define HPSA_POST_RESET_PAUSE_MSECS (3000)
>
> Ehm?

30 seconds would have sucked anyway ;)