From: Grant Grundler <grundler@parisc-linux.org>
Date: Sun, 9 Mar 2008 01:33:16 +0000 (-0700)
Subject: 2.6.25-rc4 de_stop_rxtx polling wrong
X-Git-Tag: v2.6.25-rc7~54^2~27
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=69cac988f2d8506d0b479c5ae7903b9067d7641d;p=linux-2.6

2.6.25-rc4 de_stop_rxtx polling wrong

This untested patch _should_ fix:
	"(net de2104x) Kernel panic with de2104x tulip driver on boot"
	http://bugzilla.kernel.org/show_bug.cgi?id=3156

But the bug submitter isn't responding.  Same fix has been applied
to tulip.c (several years ago) and uli526x.c (Feb 2008) drivers.

[ The panic reported in the bug report was removed in a recently
  (march 2008) accepted patch from Ondrej Zary. ]

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
---

diff --git a/drivers/net/tulip/de2104x.c b/drivers/net/tulip/de2104x.c
index 567c62757e..1b5edd646a 100644
--- a/drivers/net/tulip/de2104x.c
+++ b/drivers/net/tulip/de2104x.c
@@ -842,7 +842,7 @@ static inline int de_is_running (struct de_private *de)
 static void de_stop_rxtx (struct de_private *de)
 {
 	u32 macmode;
-	unsigned int work = 1000;
+	unsigned int i = 1300/100;
 
 	macmode = dr32(MacMode);
 	if (macmode & RxTx) {
@@ -850,10 +850,14 @@ static void de_stop_rxtx (struct de_private *de)
 		dr32(MacMode);
 	}
 
-	while (--work > 0) {
+	/* wait until in-flight frame completes.
+	 * Max time @ 10BT: 1500*8b/10Mbps == 1200us (+ 100us margin)
+	 * Typically expect this loop to end in < 50 us on 100BT.
+	 */
+	while (--i) {
 		if (!de_is_running(de))
 			return;
-		cpu_relax();
+		udelay(100);
 	}
 
 	printk(KERN_WARNING "%s: timeout expired stopping DMA\n", de->dev->name);