rt2800pci: add back ifdown hang workaround that was accidentally dropped during a compat-wireless update

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@23078 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/mac80211/patches/601-rt2x00-fix-hang-on-ifdown.patch

@@ -0,0 +1,29 @@
+From 27ed5ec6924c17b76d65b697a162bafee7bd8e4e Mon Sep 17 00:00:00 2001
+From: Helmut Schaa <helmut.schaa@googlemail.com>
+Date: Mon, 21 Jun 2010 10:03:05 +0200
+Subject: [PATCH] rt2x00: fix rt2800pci hang on ifdown
+
+rt2800pci hangs the system on rt305x SoC devices on ifdown. Work around
+this issue by disabling TX DMA prior to resetting the TX queue indices.
+
+This patch is not suitable for upstream inclusion but is just meant as
+a workaround until a proper solution is implemented.
+
+Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
+---
+ drivers/net/wireless/rt2x00/rt2800pci.c |    4 ++++
+ 1 files changed, 4 insertions(+), 0 deletions(-)
+
+--- a/drivers/net/wireless/rt2x00/rt2800pci.c
++++ b/drivers/net/wireless/rt2x00/rt2800pci.c
+@@ -585,6 +585,10 @@ static void rt2800pci_kill_tx_queue(stru
+ 		return;
+ 	}
+ 
++	rt2800_register_read(rt2x00dev, WPDMA_GLO_CFG, &reg);
++	rt2x00_set_field32(&reg, WPDMA_GLO_CFG_ENABLE_TX_DMA, 0);
++	rt2800_register_write(rt2x00dev, WPDMA_GLO_CFG, reg);
++
+ 	rt2800_register_read(rt2x00dev, WPDMA_RST_IDX, &reg);
+ 	rt2x00_set_field32(&reg, WPDMA_RST_IDX_DTX_IDX0, (queue->qid == QID_AC_BE));
+ 	rt2x00_set_field32(&reg, WPDMA_RST_IDX_DTX_IDX1, (queue->qid == QID_AC_BK));