[PATCH] wifi: mt76: mt7921s: Introduce SDIO WiFi/BT combo module card reset

[Mingyen Hsieh]

From: Leon Yen <leon.yen at mediatek.com>

Add a hardware reset method to recover from the SDIO bus error that cannot
be resolved by the current WiFi/BT subsystem reset.

Signed-off-by: Leon Yen <leon.yen at mediatek.com>
Signed-off-by: Ming Yen Hsieh <mingyen.hsieh at mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mcu.c      |  4 ++
 drivers/net/wireless/mediatek/mt76/mt76.h     |  2 +
 .../net/wireless/mediatek/mt76/mt7921/mac.c   |  2 +
 .../net/wireless/mediatek/mt76/mt7921/sdio.c  |  2 +
 .../wireless/mediatek/mt76/mt7921/sdio_mac.c  | 58 +++++++++++++++++++
 .../net/wireless/mediatek/mt76/sdio_txrx.c    |  6 +-
 6 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mcu.c b/drivers/net/wireless/mediatek/mt76/mcu.c
index 3353012e8542..65d4c2adb538 100644
--- a/drivers/net/wireless/mediatek/mt76/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mcu.c
@@ -78,6 +78,10 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb,
 	unsigned long expires;
 	int ret, seq;
 
+	if (mt76_is_sdio(dev))
+		if (test_bit(MT76_RESET, &dev->phy.state) && atomic_read(&dev->bus_hung))
+			return -EIO;
+
 	if (ret_skb)
 		*ret_skb = NULL;
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index a56d179d8cf3..e5ffe3ffd2ff 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -984,6 +984,8 @@ struct mt76_dev {
 		struct mt76_usb usb;
 		struct mt76_sdio sdio;
 	};
+
+	atomic_t bus_hung;
 };
 
 /* per-phy stats.  */
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
index ec822ff513b3..e78224ad2517 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
@@ -675,6 +675,8 @@ void mt7921_mac_reset_work(struct work_struct *work)
 		if (!ret)
 			break;
 	}
+	if (mt76_is_sdio(&dev->mt76) && atomic_read(&dev->mt76.bus_hung))
+		return;
 
 	if (i == 10)
 		dev_err(dev->mt76.dev, "chip reset failed\n");
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
index 45b9f35aab17..d8d36b3c3068 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
@@ -150,6 +150,8 @@ static int mt7921s_probe(struct sdio_func *func,
 	if (ret)
 		goto error;
 
+	atomic_set(&mdev->bus_hung, false);
+
 	mdev->rev = (mt76_rr(dev, MT_HW_CHIPID) << 16) |
 		    (mt76_rr(dev, MT_HW_REV) & 0xff);
 	dev_dbg(mdev->dev, "ASIC revision: %04x\n", mdev->rev);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/sdio_mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/sdio_mac.c
index 1f77cf71ca70..a9eb6252a904 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/sdio_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/sdio_mac.c
@@ -6,6 +6,8 @@
 #include "mt7921.h"
 #include "../mt76_connac2_mac.h"
 #include "../sdio.h"
+#include <linux/mmc/host.h>
+#include <linux/kallsyms.h>
 
 static void mt7921s_enable_irq(struct mt76_dev *dev)
 {
@@ -35,6 +37,9 @@ int mt7921s_wfsys_reset(struct mt792x_dev *dev)
 	struct mt76_sdio *sdio = &dev->mt76.sdio;
 	u32 val, status;
 
+	if (atomic_read(&dev->mt76.bus_hung))
+		return 0;
+
 	mt7921s_mcu_drv_pmctrl(dev);
 
 	sdio_claim_host(sdio->func);
@@ -91,11 +96,64 @@ int mt7921s_init_reset(struct mt792x_dev *dev)
 	return 0;
 }
 
+static struct mt76_sdio *msdio;
+static void mt7921s_card_reset(struct work_struct *work)
+{
+	struct mmc_host *sdio_host = msdio->func->card->host;
+
+	sdio_claim_host(msdio->func);
+	sdio_release_irq(msdio->func);
+	sdio_release_host(msdio->func);
+
+	mmc_remove_host(sdio_host);
+	msleep(50);
+	mmc_add_host(sdio_host);
+}
+
+static DECLARE_WORK(sdio_reset_work, mt7921s_card_reset);
+static int mt7921s_check_bus(struct mt76_dev *dev)
+{
+	struct mt76_sdio *sdio = &dev->sdio;
+	int err;
+
+	sdio_claim_host(sdio->func);
+	sdio_readl(dev->sdio.func, MCR_WHCR, &err);
+	sdio_release_host(sdio->func);
+
+	return err;
+}
+
+static int mt7921s_host_reset(struct mt792x_dev *dev)
+{
+	struct mt76_dev *mdev = &dev->mt76;
+	int err = -1;
+
+	if (!atomic_read(&mdev->bus_hung))
+		err = mt7921s_check_bus(&dev->mt76);
+
+	if (err) {
+		atomic_set(&mdev->bus_hung, true);
+		msdio = &dev->mt76.sdio;
+		dev_err(mdev->dev, "SDIO bus problem detected(%d), resetting card!!\n", err);
+		schedule_work(&sdio_reset_work);
+		return err;
+	}
+
+	atomic_set(&mdev->bus_hung, false);
+
+	return 0;
+}
+
 int mt7921s_mac_reset(struct mt792x_dev *dev)
 {
 	int err;
 
 	mt76_connac_free_pending_tx_skbs(&dev->pm, NULL);
+
+	mt7921s_host_reset(dev);
+	if (atomic_read(&dev->mt76.bus_hung))
+		return 0;
+
 	mt76_txq_schedule_all(&dev->mphy);
 	mt76_worker_disable(&dev->mt76.tx_worker);
 	set_bit(MT76_MCU_RESET, &dev->mphy.state);
diff --git a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
index 0a927a7313a6..f882d21c9f63 100644
--- a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
+++ b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
@@ -112,6 +112,7 @@ mt76s_rx_run_queue(struct mt76_dev *dev, enum mt76_rxq_id qid,
 
 	if (err < 0) {
 		dev_err(dev->dev, "sdio read data failed:%d\n", err);
+		atomic_set(&dev->bus_hung, true);
 		put_page(page);
 		return err;
 	}
@@ -234,9 +235,10 @@ static int __mt76s_xmit_queue(struct mt76_dev *dev, u8 *data, int len)
 	err = sdio_writesb(sdio->func, MCR_WTDR1, data, len);
 	sdio_release_host(sdio->func);
 
-	if (err)
+	if (err) {
 		dev_err(dev->dev, "sdio write failed: %d\n", err);
-
+		atomic_set(&dev->bus_hung, true);
+	}
 	return err;
 }
 
-- 
2.34.1