brcmfmac: make sdio suspend wait for threads to freeze

Borrowed the idea of the PM freezer to make sdio suspend wait for
watchdog and DPC thread to freeze at a safe point in their thread
routine. The suspend takes 20-25 msec.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 108 insertions, 17 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c
index 1f7e2f245e9e..c438ccdb6ed8 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c
@@ -58,6 +58,14 @@
 #define BRCMF_DEFAULT_TXGLOM_SIZE	32  /* max tx frames in glom chain */
 #define BRCMF_DEFAULT_RXGLOM_SIZE	32  /* max rx frames in glom chain */
 
+struct brcmf_sdiod_freezer {
+	atomic_t freezing;
+	atomic_t thread_count;
+	u32 frozen_count;
+	wait_queue_head_t thread_freeze;
+	struct completion resumed;
+};
+
 static int brcmf_sdiod_txglomsz = BRCMF_DEFAULT_TXGLOM_SIZE;
 module_param_named(txglomsz, brcmf_sdiod_txglomsz, int, 0);
 MODULE_PARM_DESC(txglomsz, "maximum tx packet chain size [SDIO]");
@@ -895,6 +903,87 @@ static void brcmf_sdiod_sgtable_alloc(struct brcmf_sdio_dev *sdiodev)
 	sdiodev->txglomsz = brcmf_sdiod_txglomsz;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int brcmf_sdiod_freezer_attach(struct brcmf_sdio_dev *sdiodev)
+{
+	sdiodev->freezer = kzalloc(sizeof(*sdiodev->freezer), GFP_KERNEL);
+	if (!sdiodev->freezer)
+		return -ENOMEM;
+	atomic_set(&sdiodev->freezer->thread_count, 0);
+	atomic_set(&sdiodev->freezer->freezing, 0);
+	init_waitqueue_head(&sdiodev->freezer->thread_freeze);
+	init_completion(&sdiodev->freezer->resumed);
+	return 0;
+}
+
+static void brcmf_sdiod_freezer_detach(struct brcmf_sdio_dev *sdiodev)
+{
+	if (sdiodev->freezer) {
+		WARN_ON(atomic_read(&sdiodev->freezer->freezing));
+		kfree(sdiodev->freezer);
+	}
+}
+
+static int brcmf_sdiod_freezer_on(struct brcmf_sdio_dev *sdiodev)
+{
+	atomic_t *expect = &sdiodev->freezer->thread_count;
+	int res = 0;
+
+	sdiodev->freezer->frozen_count = 0;
+	reinit_completion(&sdiodev->freezer->resumed);
+	atomic_set(&sdiodev->freezer->freezing, 1);
+	brcmf_sdio_trigger_dpc(sdiodev->bus);
+	wait_event(sdiodev->freezer->thread_freeze,
+		   atomic_read(expect) == sdiodev->freezer->frozen_count);
+	sdio_claim_host(sdiodev->func[1]);
+	res = brcmf_sdio_sleep(sdiodev->bus, true);
+	sdio_release_host(sdiodev->func[1]);
+	return res;
+}
+
+static void brcmf_sdiod_freezer_off(struct brcmf_sdio_dev *sdiodev)
+{
+	sdio_claim_host(sdiodev->func[1]);
+	brcmf_sdio_sleep(sdiodev->bus, false);
+	sdio_release_host(sdiodev->func[1]);
+	atomic_set(&sdiodev->freezer->freezing, 0);
+	complete_all(&sdiodev->freezer->resumed);
+}
+
+bool brcmf_sdiod_freezing(struct brcmf_sdio_dev *sdiodev)
+{
+	return atomic_read(&sdiodev->freezer->freezing);
+}
+
+void brcmf_sdiod_try_freeze(struct brcmf_sdio_dev *sdiodev)
+{
+	if (!brcmf_sdiod_freezing(sdiodev))
+		return;
+	sdiodev->freezer->frozen_count++;
+	wake_up(&sdiodev->freezer->thread_freeze);
+	wait_for_completion(&sdiodev->freezer->resumed);
+}
+
+void brcmf_sdiod_freezer_count(struct brcmf_sdio_dev *sdiodev)
+{
+	atomic_inc(&sdiodev->freezer->thread_count);
+}
+
+void brcmf_sdiod_freezer_uncount(struct brcmf_sdio_dev *sdiodev)
+{
+	atomic_dec(&sdiodev->freezer->thread_count);
+}
+#else
+static int brcmf_sdiod_freezer_attach(struct brcmf_sdio_dev *sdiodev)
+{
+	return 0;
+}
+
+static void brcmf_sdiod_freezer_detach(struct brcmf_sdio_dev *sdiodev)
+{
+}
+#endif /* CONFIG_PM_SLEEP */
+
 static int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev)
 {
 	if (sdiodev->bus) {
@@ -902,6 +991,8 @@ static int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev)
 		sdiodev->bus = NULL;
 	}
 
+	brcmf_sdiod_freezer_detach(sdiodev);
+
 	/* Disable Function 2 */
 	sdio_claim_host(sdiodev->func[2]);
 	sdio_disable_func(sdiodev->func[2]);
@@ -973,6 +1064,10 @@ static int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev)
 	 */
 	brcmf_sdiod_sgtable_alloc(sdiodev);
 
+	ret = brcmf_sdiod_freezer_attach(sdiodev);
+	if (ret)
+		goto out;
+
 	/* try to attach to the target device */
 	sdiodev->bus = brcmf_sdio_probe(sdiodev);
 	if (!sdiodev->bus) {
@@ -1069,9 +1164,6 @@ static int brcmf_ops_sdio_probe(struct sdio_func *func,
 #endif
 
 	brcmf_sdiod_change_state(sdiodev, BRCMF_SDIOD_DOWN);
-	sdiodev->sleeping = false;
-	atomic_set(&sdiodev->suspend, false);
-	init_waitqueue_head(&sdiodev->idle_wait);
 
 	brcmf_dbg(SDIO, "F2 found, calling brcmf_sdiod_probe...\n");
 	err = brcmf_sdiod_probe(sdiodev);
@@ -1133,24 +1225,22 @@ void brcmf_sdio_wowl_config(struct device *dev, bool enabled)
 #ifdef CONFIG_PM_SLEEP
 static int brcmf_ops_sdio_suspend(struct device *dev)
 {
+	struct sdio_func *func;
 	struct brcmf_bus *bus_if;
 	struct brcmf_sdio_dev *sdiodev;
 	mmc_pm_flag_t sdio_flags;
 
-	brcmf_dbg(SDIO, "Enter\n");
+	func = container_of(dev, struct sdio_func, dev);
+	brcmf_dbg(SDIO, "Enter: F%d\n", func->num);
+	if (func->num != SDIO_FUNC_1)
+		return 0;
+
 
 	bus_if = dev_get_drvdata(dev);
 	sdiodev = bus_if->bus_priv.sdio;
 
-	/* wait for watchdog to go idle */
-	if (wait_event_timeout(sdiodev->idle_wait, sdiodev->sleeping,
-			       msecs_to_jiffies(3 * BRCMF_WD_POLL_MS)) == 0) {
-		brcmf_err("bus still active\n");
-		return -EBUSY;
-	}
-	/* disable watchdog */
+	brcmf_sdiod_freezer_on(sdiodev);
 	brcmf_sdio_wd_timer(sdiodev->bus, 0);
-	atomic_set(&sdiodev->suspend, true);
 
 	if (sdiodev->wowl_enabled) {
 		sdio_flags = MMC_PM_KEEP_POWER;
@@ -1168,12 +1258,13 @@ static int brcmf_ops_sdio_resume(struct device *dev)
 {
 	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
 	struct brcmf_sdio_dev *sdiodev = bus_if->bus_priv.sdio;
+	struct sdio_func *func = container_of(dev, struct sdio_func, dev);
 
-	brcmf_dbg(SDIO, "Enter\n");
-	if (sdiodev->pdata && sdiodev->pdata->oob_irq_supported)
-		disable_irq_wake(sdiodev->pdata->oob_irq_nr);
-	brcmf_sdio_wd_timer(sdiodev->bus, BRCMF_WD_POLL_MS);
-	atomic_set(&sdiodev->suspend, false);
+	brcmf_dbg(SDIO, "Enter: F%d\n", func->num);
+	if (func->num != SDIO_FUNC_2)
+		return 0;
+
+	brcmf_sdiod_freezer_off(sdiodev);
 	return 0;
 }