Messages in this thread | | | Date | Fri, 12 May 2006 12:53:31 -0400 | From | Mark Hounschell <> | Subject | Re: 3c59x vortex_timer rt hack |
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Steven Rostedt wrote: > On Fri, 12 May 2006, Andrew Morton wrote: > >> Steven Rostedt <rostedt@goodmis.org> wrote: >>> Use this patch instead. It needs an irq disable. But, believe it or not, >>> on SMP this is actually better. If the irq is shared (as it is in Mark's >>> case), we don't stop the irq of other devices from being handled on >>> another CPU (unfortunately for Mark, he pinned all interrupts to one CPU). >>> >>> Andrew, >>> >>> should this be changed in mainline too? >> I suppose so - we're taking the lock with spin_lock_bh(), but it can also >> be taken by this CPU from the interrupt, so it'll deadlock. But lo! We've >> done disable_irq(), so the interrupt won't be happening. >> >> So yes, doing spin_lock_irq() (irqrestore isn't needed in a timer handler) >> instead of disable_irq() in vortex_timer() looks OK. > > Ah, you're right, it's an over kill. > > Ingo, here's the patch without irqsave > > -- Steve > > Index: linux-2.6.16-rt20/drivers/net/3c59x.c > =================================================================== > --- linux-2.6.16-rt20.orig/drivers/net/3c59x.c 2006-05-12 10:27:36.000000000 -0400 > +++ linux-2.6.16-rt20/drivers/net/3c59x.c 2006-05-12 11:03:39.000000000 -0400 > @@ -1897,7 +1897,7 @@ vortex_timer(unsigned long data) > > if (vp->medialock) > goto leave_media_alone; > - disable_irq(dev->irq); > + spin_lock_irq(&vp->lock); > old_window = ioread16(ioaddr + EL3_CMD) >> 13; > EL3WINDOW(4); > media_status = ioread16(ioaddr + Wn4_Media); > @@ -1919,7 +1919,6 @@ vortex_timer(unsigned long data) > break; > case XCVR_MII: case XCVR_NWAY: > { > - spin_lock_bh(&vp->lock); > mii_status = mdio_read(dev, vp->phys[0], MII_BMSR); > if (!(mii_status & BMSR_LSTATUS)) { > /* Re-read to get actual link status */ > @@ -1957,7 +1956,6 @@ vortex_timer(unsigned long data) > } else { > netif_carrier_off(dev); > } > - spin_unlock_bh(&vp->lock); > } > break; > default: /* Other media types handled by Tx timeouts. */ > @@ -2000,7 +1998,7 @@ vortex_timer(unsigned long data) > /* AKPM: FIXME: Should reset Rx & Tx here. P60 of 3c90xc.pdf */ > } > EL3WINDOW(old_window); > - enable_irq(dev->irq); > + spin_unlock_irq(&vp->lock); > > leave_media_alone: > if (vortex_debug > 2) >
I have tried this one and it seems OK. No BUGs or disconnections for over an hour now and I'm beating it good.
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