[kernel] r15689 - in dists/sid/linux-2.6/debian: . patches/bugfix/all patches/series

[Ben Hutchings]

Author: benh
Date: Sun May 16 03:49:36 2010
New Revision: 15689

Log:
3c503: Fix IRQ probing (Closes: #566522)

Added:
   dists/sid/linux-2.6/debian/patches/bugfix/all/3c503-Fix-IRQ-probing.patch
Modified:
   dists/sid/linux-2.6/debian/changelog
   dists/sid/linux-2.6/debian/patches/series/13

Modified: dists/sid/linux-2.6/debian/changelog
==============================================================================
--- dists/sid/linux-2.6/debian/changelog	Sat May 15 19:55:28 2010	(r15688)
+++ dists/sid/linux-2.6/debian/changelog	Sun May 16 03:49:36 2010	(r15689)
@@ -38,6 +38,7 @@
   * partitions: Rescan partition tables after HPA is disabled
   * libata: Disable HPA if it is only enabled after suspend
   * V4L/DVB: budget: Select correct frontend drivers (Closes: #575223)
+  * 3c503: Fix IRQ probing (Closes: #566522)
 
   [ Aurelien Jarno ]
   * mips/swarm: fix boot from IDE based media (Sebastian Andrzej Siewior)

Added: dists/sid/linux-2.6/debian/patches/bugfix/all/3c503-Fix-IRQ-probing.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/bugfix/all/3c503-Fix-IRQ-probing.patch	Sun May 16 03:49:36 2010	(r15689)
@@ -0,0 +1,101 @@
+From: Ben Hutchings <ben at decadent.org.uk>
+Date: Wed, 7 Apr 2010 20:55:47 -0700
+Subject: [PATCH] 3c503: Fix IRQ probing
+
+The driver attempts to select an IRQ for the NIC automatically by
+testing which of the supported IRQs are available and then probing
+each available IRQ with probe_irq_{on,off}().  There are obvious race
+conditions here, besides which:
+1. The test for availability is done by passing a NULL handler, which
+   now always returns -EINVAL, thus the device cannot be opened:
+   <http://bugs.debian.org/566522>
+2. probe_irq_off() will report only the first ISA IRQ handled,
+   potentially leading to a false negative.
+
+There was another bug that meant it ignored all error codes from
+request_irq() except -EBUSY, so it would 'succeed' despite this
+(possibly causing conflicts with other ISA devices).  This was fixed
+by ab08999d6029bb2c79c16be5405d63d2bedbdfea 'WARNING: some
+request_irq() failures ignored in el2_open()', which exposed bug 1.
+
+This patch:
+1. Replaces the use of probe_irq_{on,off}() with a real interrupt handler
+2. Adds a delay before checking the interrupt-seen flag
+3. Disables interrupts on all failure paths
+4. Distinguishes error codes from the second request_irq() call,
+   consistently with the first
+
+Compile-tested only.
+
+Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
+---
+ drivers/net/3c503.c |   42 ++++++++++++++++++++++++++++++------------
+ 1 files changed, 30 insertions(+), 12 deletions(-)
+
+diff --git a/drivers/net/3c503.c b/drivers/net/3c503.c
+index 66e0323..b74a0ea 100644
+--- a/drivers/net/3c503.c
++++ b/drivers/net/3c503.c
+@@ -380,6 +380,12 @@ out:
+     return retval;
+ }
+ 
++static irqreturn_t el2_probe_interrupt(int irq, void *seen)
++{
++	*(bool *)seen = true;
++	return IRQ_HANDLED;
++}
++
+ static int
+ el2_open(struct net_device *dev)
+ {
+@@ -391,22 +397,35 @@ el2_open(struct net_device *dev)
+ 
+ 	outb(EGACFR_NORM, E33G_GACFR);	/* Enable RAM and interrupts. */
+ 	do {
+-	    retval = request_irq(*irqp, NULL, 0, "bogus", dev);
+-	    if (retval >= 0) {
++		bool seen;
++
++		retval = request_irq(*irqp, el2_probe_interrupt, 0,
++				     dev->name, &seen);
++		if (retval == -EBUSY)
++			continue;
++		if (retval < 0)
++			goto err_disable;
++
+ 		/* Twinkle the interrupt, and check if it's seen. */
+-		unsigned long cookie = probe_irq_on();
++		seen = false;
++		smp_wmb();
+ 		outb_p(0x04 << ((*irqp == 9) ? 2 : *irqp), E33G_IDCFR);
+ 		outb_p(0x00, E33G_IDCFR);
+-		if (*irqp == probe_irq_off(cookie)	/* It's a good IRQ line! */
+-		    && ((retval = request_irq(dev->irq = *irqp,
+-		    eip_interrupt, 0, dev->name, dev)) == 0))
+-		    break;
+-	    } else {
+-		    if (retval != -EBUSY)
+-			    return retval;
+-	    }
++		msleep(1);
++		free_irq(*irqp, el2_probe_interrupt);
++		if (!seen)
++			continue;
++
++		retval = request_irq(dev->irq = *irqp, eip_interrupt, 0,
++				     dev->name, dev);
++		if (retval == -EBUSY)
++			continue;
++		if (retval < 0)
++			goto err_disable;
+ 	} while (*++irqp);
++
+ 	if (*irqp == 0) {
++	err_disable:
+ 	    outb(EGACFR_IRQOFF, E33G_GACFR);	/* disable interrupts. */
+ 	    return -EAGAIN;
+ 	}
+-- 
+1.7.1
+

Modified: dists/sid/linux-2.6/debian/patches/series/13
==============================================================================
--- dists/sid/linux-2.6/debian/patches/series/13	Sat May 15 19:55:28 2010	(r15688)
+++ dists/sid/linux-2.6/debian/patches/series/13	Sun May 16 03:49:36 2010	(r15689)
@@ -31,3 +31,4 @@
 + bugfix/all/libata-implement-on-demand-HPA-unlocking.patch
 + bugfix/all/V4L-DVB-budget-Select-correct-frontends.patch
 + bugfix/all/drm-edid-Fix-1024x768 at 85Hz.patch
++ bugfix/all/3c503-Fix-IRQ-probing.patch