From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 4 Jul 2010 01:31:33 +0000 (+0000)
Subject: ag71xx: fix a memory corruption bug that happens if you flood the interface with... 
X-Git-Url: http://git.openwrt.org/?p=openwrt%2Fsvn-archive%2Farchive.git;a=commitdiff_plain;h=c3ba75a7cbe6d4d256b345a55511fc89a3cbb14c

ag71xx: fix a memory corruption bug that happens if you flood the interface with packets while it's being brought down
fixes boot time crashes under load reported by matteo

SVN-Revision: 22054
---

diff --git a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
index a57b6d46fc..9fd41527dd 100644
--- a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
+++ b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
@@ -454,6 +454,12 @@ static void ag71xx_dma_reset(struct ag71xx *ag)
 	ag71xx_wr(ag, AG71XX_REG_RX_CTRL, 0);
 	ag71xx_wr(ag, AG71XX_REG_TX_CTRL, 0);
 
+	/*
+	 * give the hardware some time to really stop all rx/tx activity
+	 * clearing the descriptors too early causes random memory corruption
+	 */
+	mdelay(1);
+
 	/* clear descriptor addresses */
 	ag71xx_wr(ag, AG71XX_REG_TX_DESC, 0);
 	ag71xx_wr(ag, AG71XX_REG_RX_DESC, 0);