brcmfmac: Simplify watchdog sleep.

The watchdog thread is used to put the SDIO bus to sleep when the
system is idling. This patch simplifies the way it is determined
when sleep can be entered.
Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/brcm80211/brcmfmac/sdio.c

@@ -485,7 +485,6 @@ struct brcmf_sdio {
 #endif				/* DEBUG */
 
 	uint clkstate;		/* State of sd and backplane clock(s) */
-	bool activity;		/* Activity flag for clock down */
 	s32 idletime;		/* Control for activity timeout */
 	s32 idlecount;		/* Activity timeout counter */
 	s32 idleclock;		/* How to set bus driver when idle */
@@ -511,6 +510,7 @@ struct brcmf_sdio {
 	struct workqueue_struct *brcmf_wq;
 	struct work_struct datawork;
 	atomic_t dpc_tskcnt;
+	atomic_t dpc_running;
 
 	bool txoff;		/* Transmit flow-controlled */
 	struct brcmf_sdio_count sdcnt;
@@ -959,13 +959,8 @@ static int brcmf_sdio_clkctl(struct brcmf_sdio *bus, uint target, bool pendok)
 	brcmf_dbg(SDIO, "Enter\n");
 
 	/* Early exit if we're already there */
-	if (bus->clkstate == target) {
-		if (target == CLK_AVAIL) {
-			brcmf_sdio_wd_timer(bus, BRCMF_WD_POLL_MS);
-			bus->activity = true;
-		}
+	if (bus->clkstate == target)
 		return 0;
-	}
 
 	switch (target) {
 	case CLK_AVAIL:
@@ -975,7 +970,6 @@ static int brcmf_sdio_clkctl(struct brcmf_sdio *bus, uint target, bool pendok)
 		/* Now request HT Avail on the backplane */
 		brcmf_sdio_htclk(bus, true, pendok);
 		brcmf_sdio_wd_timer(bus, BRCMF_WD_POLL_MS);
-		bus->activity = true;
 		break;
 
 	case CLK_SDONLY:
@@ -1024,17 +1018,6 @@ brcmf_sdio_bus_sleep(struct brcmf_sdio *bus, bool sleep, bool pendok)
 
 		/* Going to sleep */
 		if (sleep) {
-			/* Don't sleep if something is pending */
-			if (atomic_read(&bus->intstatus) ||
-			    atomic_read(&bus->ipend) > 0 ||
-			    bus->ctrl_frame_stat ||
-			    (!atomic_read(&bus->fcstate) &&
-			    brcmu_pktq_mlen(&bus->txq, ~bus->flowcontrol) &&
-			    data_ok(bus))) {
-				 err = -EBUSY;
-				 goto done;
-			}
-
 			clkcsr = brcmf_sdiod_regrb(bus->sdiodev,
 						   SBSDIO_FUNC1_CHIPCLKCSR,
 						   &err);
@@ -1045,11 +1028,7 @@ brcmf_sdio_bus_sleep(struct brcmf_sdio *bus, bool sleep, bool pendok)
 						  SBSDIO_ALP_AVAIL_REQ, &err);
 			}
 			err = brcmf_sdio_kso_control(bus, false);
-			/* disable watchdog */
-			if (!err)
-				brcmf_sdio_wd_timer(bus, 0);
 		} else {
-			bus->idlecount = 0;
 			err = brcmf_sdio_kso_control(bus, true);
 		}
 		if (err) {
@@ -3566,7 +3545,7 @@ void brcmf_sdio_isr(struct brcmf_sdio *bus)
 	queue_work(bus->brcmf_wq, &bus->datawork);
 }
 
-static bool brcmf_sdio_bus_watchdog(struct brcmf_sdio *bus)
+static void brcmf_sdio_bus_watchdog(struct brcmf_sdio *bus)
 {
 	brcmf_dbg(TIMER, "Enter\n");
 
@@ -3627,22 +3606,21 @@ static bool brcmf_sdio_bus_watchdog(struct brcmf_sdio *bus)
 #endif				/* DEBUG */
 
 	/* On idle timeout clear activity flag and/or turn off clock */
-	if ((bus->idletime > 0) && (bus->clkstate == CLK_AVAIL)) {
-		if (++bus->idlecount >= bus->idletime) {
-			bus->idlecount = 0;
-			if (bus->activity) {
-				bus->activity = false;
-				brcmf_sdio_wd_timer(bus, BRCMF_WD_POLL_MS);
-			} else {
+	if ((atomic_read(&bus->dpc_tskcnt) == 0) &&
+	    (atomic_read(&bus->dpc_running) == 0) &&
+	    (bus->idletime > 0) && (bus->clkstate == CLK_AVAIL)) {
+		bus->idlecount++;
+		if (bus->idlecount > bus->idletime) {
 			brcmf_dbg(SDIO, "idle\n");
 			sdio_claim_host(bus->sdiodev->func[1]);
+			brcmf_sdio_wd_timer(bus, 0);
+			bus->idlecount = 0;
 			brcmf_sdio_bus_sleep(bus, true, false);
 			sdio_release_host(bus->sdiodev->func[1]);
 		}
+	} else {
+		bus->idlecount = 0;
 	}
-	}
-
-	return (atomic_read(&bus->ipend) > 0);
 }
 
 static void brcmf_sdio_dataworker(struct work_struct *work)
@@ -3651,8 +3629,11 @@ static void brcmf_sdio_dataworker(struct work_struct *work)
 					      datawork);
 
 	while (atomic_read(&bus->dpc_tskcnt)) {
+		atomic_set(&bus->dpc_running, 1);
 		atomic_set(&bus->dpc_tskcnt, 0);
 		brcmf_sdio_dpc(bus);
+		bus->idlecount = 0;
+		atomic_set(&bus->dpc_running, 0);
 	}
 	if (brcmf_sdiod_freezing(bus->sdiodev)) {
 		brcmf_sdiod_change_state(bus->sdiodev, BRCMF_SDIOD_DOWN);
@@ -4154,6 +4135,7 @@ struct brcmf_sdio *brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev)
 	}
 	/* Initialize DPC thread */
 	atomic_set(&bus->dpc_tskcnt, 0);
+	atomic_set(&bus->dpc_running, 0);
 
 	/* Assign bus interface call back */
 	bus->sdiodev->bus_if->dev = bus->sdiodev->dev;