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SubjectRe: [PATCH 1/1] megaraid_{mm,mbox}: fix a bug in reset handler
Andrew Morton <akpm@osdl.org> wrote:
>
> > @@ -2918,12 +2933,12 @@
> > wmb();
> > WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);
> >
> > - for (i = 0; i < 0xFFFFF; i++) {
> > + for (i = 0; i < 0xFFFFFF; i++) {
> > if (mbox->numstatus != 0xFF) break;
> > rmb();
> > }
>
> Oh my. That's an awfully long interrupts-off spin.

And if that mbox is in main memory, the duration of this spin will vary by
a factor of many tens across all the different machines on which this
driver must operate.

Careful use of ndelay() or udelay() would fix that.
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