libertas: fix power save issue in libertas_sdio module

The problem: "iwconfig ethX power on" returns error

The cause: "ps_supported" flag was never set for SD8385/8686

The fix: check firmware capabilities returned by GET_HW_SPEC command.
Set "ps_supported" to 1 if FW_CAPINFO_PS bit is on. This fix applies
to SDIO interface only.
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/defs.h

@@ -265,6 +265,7 @@ static inline void lbs_deb_hex(unsigned int grp, const char *prompt, u8 *buf, in
 
 #define	CMD_F_HOSTCMD		(1 << 0)
 #define FW_CAPINFO_WPA  	(1 << 0)
+#define FW_CAPINFO_PS  		(1 << 1)
 #define FW_CAPINFO_FIRMWARE_UPGRADE	(1 << 13)
 #define FW_CAPINFO_BOOT2_UPGRADE	(1<<14)
 #define FW_CAPINFO_PERSISTENT_CONFIG	(1<<15)

drivers/net/wireless/libertas/if_sdio.c

@@ -209,6 +209,9 @@ static int if_sdio_handle_event(struct if_sdio_card *card,
 		event = sdio_readb(card->func, IF_SDIO_EVENT, &ret);
 		if (ret)
 			goto out;
+
+		/* right shift 3 bits to get the event id */
+		event >>= 3;
 	} else {
 		if (size < 4) {
 			lbs_deb_sdio("event packet too small (%d bytes)\n",
@@ -921,6 +924,9 @@ static int if_sdio_probe(struct sdio_func *func,
 	if (ret)
 		goto err_activate_card;
 
+	if (priv->fwcapinfo & FW_CAPINFO_PS)
+		priv->ps_supported = 1;
+
 out:
 	lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);