zd1211rw: wait between setting hash table and powering radio on

I am running Debian testing kernel 3.1.0-1-amd64, using a 079b:0062 Sagem
XG-76NA 802.11bg stick.

Upon zd1211rw interface
bringup (ifconfig wlan0 up) I get the following timeout:

[  950.330573] zd1211rw 1-3:1.0: phy2
[  955.108510] zd1211rw 1-3:1.0: firmware version 4725
[  955.148532] zd1211rw 1-3:1.0: zd1211b chip 079b:0062 v4810 high 00-19-70
AL2230_RF pa0 g--NS
[snip]
[  955.204072] zd1211rw 1-3:1.0: error ioread32(CR_REG1): -110

A second ifconfig wlan0 up brings the interface up without problems.

After a bit more debugging, the call trace is the following:

[10241.028130] zd1211rw 1-3:1.0: zd_chip_lock_phy_regs: error
ioread32(CR_REG1): -110
[10241.028140] zd1211rw 1-3:1.0: zd_switch_radio_on: failed to lock PHY regs
[10241.028148] zd1211rw 1-3:1.0: zd_op_start: failed to set radio on

Adding a 10 milliseconds delay between the call to set_mc_hash() and
zd_chip_switch_radio_on() allows successful interface bringups in all
cases and matches what the vendor driver did.
Acked-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/zd1211rw/zd_mac.c

@@ -306,9 +306,19 @@ int zd_op_start(struct ieee80211_hw *hw)
 	r = set_mc_hash(mac);
 	if (r)
 		goto disable_int;
+
+	/* Wait after setting the multicast hash table and powering on
+	 * the radio otherwise interface bring up will fail. This matches
+	 * what the vendor driver did.
+	 */
+	msleep(10);
+
 	r = zd_chip_switch_radio_on(chip);
-	if (r < 0)
+	if (r < 0) {
+		dev_err(zd_chip_dev(chip),
+			"%s: failed to set radio on\n", __func__);
 		goto disable_int;
+	}
 	r = zd_chip_enable_rxtx(chip);
 	if (r < 0)
 		goto disable_radio;