wl1271: Implement delayed entry into ELP

Implement delayed entry into ELP. This will promote the following:
 - Less redundant sleep/wake cycles (better perf)
 - Avoids known firmware issues with going to ELP too fast after an
   operation

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Vidhya Govindan <vidhya.govindan@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 35 insertions, 15 deletions

diff --git a/drivers/net/wireless/wl12xx/wl1271.h b/drivers/net/wireless/wl12xx/wl1271.h
index e575dcc9df27..c455dcbae524 100644
--- a/drivers/net/wireless/wl12xx/wl1271.h
+++ b/drivers/net/wireless/wl12xx/wl1271.h
@@ -373,6 +373,7 @@ struct wl1271 {
         bool elp;
 
         struct completion *elp_compl;
+        struct delayed_work elp_work;
 
         /* we can be in psm, but not in elp, we have to differentiate */
         bool psm;
diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index 3d629daf2246..cc5c3285deac 100644
--- a/drivers/net/wireless/wl12xx/wl1271_main.c
+++ b/drivers/net/wireless/wl12xx/wl1271_main.c
@@ -1226,6 +1226,7 @@ static int __devinit wl1271_probe(struct spi_device *spi)
         skb_queue_head_init(&wl->tx_queue);
 
         INIT_WORK(&wl->filter_work, wl1271_filter_work);
+        INIT_DELAYED_WORK(&wl->elp_work, wl1271_elp_work);
         wl->channel = WL1271_DEFAULT_CHANNEL;
         wl->scanning = false;
         wl->default_key = 0;
diff --git a/drivers/net/wireless/wl12xx/wl1271_ps.c b/drivers/net/wireless/wl12xx/wl1271_ps.c
index 1dc74b0c7736..0f6ea16cae83 100644
--- a/drivers/net/wireless/wl12xx/wl1271_ps.c
+++ b/drivers/net/wireless/wl12xx/wl1271_ps.c
@@ -27,25 +27,43 @@
 
 #define WL1271_WAKEUP_TIMEOUT 500
 
-/* Routines to toggle sleep mode while in ELP */
-void wl1271_ps_elp_sleep(struct wl1271 *wl)
+void wl1271_elp_work(struct work_struct *work)
 {
+        struct delayed_work *dwork;
+        struct wl1271 *wl;
+
+        dwork = container_of(work, struct delayed_work, work);
+        wl = container_of(dwork, struct wl1271, elp_work);
+
+        wl1271_debug(DEBUG_PSM, "elp work");
+
+        mutex_lock(&wl->mutex);
+
         /*
-         * FIXME: due to a problem in the firmware (causing a firmware
-         * crash), ELP entry is prevented below. Remove the "true" to
-         * re-enable ELP entry.
+         * FIXME: below, by means of the "true", ELP has been disabled for now
+         * to work around a firmware bug. To be enabled upon receiving a new
+         * firmware version.
          */
         if (true || wl->elp || !wl->psm)
-                return;
+                goto out;
 
-        /*
-         * Go to ELP unless there is work already pending - pending work
-         * will immediately wakeup the chipset anyway.
-         */
-        if (!work_pending(&wl->irq_work) && !work_pending(&wl->tx_work)) {
-                wl1271_debug(DEBUG_PSM, "chip to elp");
-                wl1271_write32(wl, HW_ACCESS_ELP_CTRL_REG_ADDR, ELPCTRL_SLEEP);
-                wl->elp = true;
+        wl1271_debug(DEBUG_PSM, "chip to elp");
+        wl1271_write32(wl, HW_ACCESS_ELP_CTRL_REG_ADDR, ELPCTRL_SLEEP);
+        wl->elp = true;
+
+out:
+        mutex_unlock(&wl->mutex);
+}
+
+#define ELP_ENTRY_DELAY  5
+
+/* Routines to toggle sleep mode while in ELP */
+void wl1271_ps_elp_sleep(struct wl1271 *wl)
+{
+        if (wl->psm) {
+                cancel_delayed_work(&wl->elp_work);
+                ieee80211_queue_delayed_work(wl->hw, &wl->elp_work,
+                                        msecs_to_jiffies(ELP_ENTRY_DELAY));
         }
 }
 
diff --git a/drivers/net/wireless/wl12xx/wl1271_ps.h b/drivers/net/wireless/wl12xx/wl1271_ps.h
index de2bd3c7dc9c..779653d0ae85 100644
--- a/drivers/net/wireless/wl12xx/wl1271_ps.h
+++ b/drivers/net/wireless/wl12xx/wl1271_ps.h
@@ -30,6 +30,6 @@
 int wl1271_ps_set_mode(struct wl1271 *wl, enum wl1271_cmd_ps_mode mode);
 void wl1271_ps_elp_sleep(struct wl1271 *wl);
 int wl1271_ps_elp_wakeup(struct wl1271 *wl, bool chip_awake);
-
+void wl1271_elp_work(struct work_struct *work);
 
 #endif /* __WL1271_PS_H__ */