Messages in this thread Patch in this message | | | Date | Fri, 12 May 2006 11:04:50 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: 3c59x vortex_timer rt hack (was: rt20 patch question) |
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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) - 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/
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