wl1271: Implement looped IRQ handling

This patch implements looped IRQ handling. In essence, if a new interrupt is
asserted by the FW while the host is processing the previous one, the host
will directly proceed processing the new IRQ without leaving the handling
function.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 47 insertions, 29 deletions

diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index a46d323f8a6e..9f7416864053 100644
--- a/drivers/net/wireless/wl12xx/wl1271_main.c
+++ b/drivers/net/wireless/wl12xx/wl1271_main.c
@@ -406,10 +406,14 @@ static void wl1271_fw_status(struct wl1271 *wl,
                 le32_to_cpu(status->fw_localtime);
 }
 
+#define WL1271_IRQ_MAX_LOOPS 10
+
 static void wl1271_irq_work(struct work_struct *work)
 {
         int ret;
         u32 intr;
+        int loopcount = WL1271_IRQ_MAX_LOOPS;
+        unsigned long flags;
         struct wl1271 *wl =
                 container_of(work, struct wl1271, irq_work);
 
@@ -417,51 +421,65 @@ static void wl1271_irq_work(struct work_struct *work)
 
         wl1271_debug(DEBUG_IRQ, "IRQ work");
 
-        if (wl->state == WL1271_STATE_OFF)
+        if (unlikely(wl->state == WL1271_STATE_OFF))
                 goto out;
 
         ret = wl1271_ps_elp_wakeup(wl, true);
         if (ret < 0)
                 goto out;
 
-        wl1271_fw_status(wl, wl->fw_status);
-        intr = le32_to_cpu(wl->fw_status->intr);
-        if (!intr) {
-                wl1271_debug(DEBUG_IRQ, "Zero interrupt received.");
-                goto out_sleep;
-        }
+        spin_lock_irqsave(&wl->wl_lock, flags);
+        while (test_bit(WL1271_FLAG_IRQ_PENDING, &wl->flags) && loopcount) {
+                clear_bit(WL1271_FLAG_IRQ_PENDING, &wl->flags);
+                spin_unlock_irqrestore(&wl->wl_lock, flags);
+                loopcount--;
 
-        intr &= WL1271_INTR_MASK;
+                wl1271_fw_status(wl, wl->fw_status);
+                intr = le32_to_cpu(wl->fw_status->intr);
+                if (!intr) {
+                        wl1271_debug(DEBUG_IRQ, "Zero interrupt received.");
+                        continue;
+                }
 
-        if (intr & WL1271_ACX_INTR_EVENT_A) {
-                wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_EVENT_A");
-                wl1271_event_handle(wl, 0);
-        }
+                intr &= WL1271_INTR_MASK;
 
-        if (intr & WL1271_ACX_INTR_EVENT_B) {
-                wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_EVENT_B");
-                wl1271_event_handle(wl, 1);
-        }
+                if (intr & WL1271_ACX_INTR_DATA) {
+                        wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_DATA");
 
-        if (intr & WL1271_ACX_INTR_INIT_COMPLETE)
-                wl1271_debug(DEBUG_IRQ,
-                             "WL1271_ACX_INTR_INIT_COMPLETE");
+                        /* check for tx results */
+                        if (wl->fw_status->tx_results_counter !=
+                            (wl->tx_results_count & 0xff))
+                                wl1271_tx_complete(wl);
 
-        if (intr & WL1271_ACX_INTR_HW_AVAILABLE)
-                wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_HW_AVAILABLE");
+                        wl1271_rx(wl, wl->fw_status);
+                }
+
+                if (intr & WL1271_ACX_INTR_EVENT_A) {
+                        wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_EVENT_A");
+                        wl1271_event_handle(wl, 0);
+                }
+
+                if (intr & WL1271_ACX_INTR_EVENT_B) {
+                        wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_EVENT_B");
+                        wl1271_event_handle(wl, 1);
+                }
 
-        if (intr & WL1271_ACX_INTR_DATA) {
-                wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_DATA");
+                if (intr & WL1271_ACX_INTR_INIT_COMPLETE)
+                        wl1271_debug(DEBUG_IRQ,
+                                     "WL1271_ACX_INTR_INIT_COMPLETE");
 
-                /* check for tx results */
-                if (wl->fw_status->tx_results_counter !=
-                    (wl->tx_results_count & 0xff))
-                        wl1271_tx_complete(wl);
+                if (intr & WL1271_ACX_INTR_HW_AVAILABLE)
+                        wl1271_debug(DEBUG_IRQ, "WL1271_ACX_INTR_HW_AVAILABLE");
 
-                wl1271_rx(wl, wl->fw_status);
+                spin_lock_irqsave(&wl->wl_lock, flags);
         }
 
-out_sleep:
+        if (test_bit(WL1271_FLAG_IRQ_PENDING, &wl->flags))
+                ieee80211_queue_work(wl->hw, &wl->irq_work);
+        else
+                clear_bit(WL1271_FLAG_IRQ_RUNNING, &wl->flags);
+        spin_unlock_irqrestore(&wl->wl_lock, flags);
+
         wl1271_ps_elp_sleep(wl);
 
 out: