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From:   Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
To:     marcel@holtmann.org, linux-bluetooth@vger.kernel.org,
        ulf.hansson@linaro.org
Cc:     chromeos-bluetooth-upstreaming@chromium.org, mka@chromium.org,
        dianders@chromium.org,
        Abhishek Pandit-Subedi <abhishekpandit@chromium.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/1] Bluetooth: btmrvl: Detect hangs and force a reset of the SDIO card
Date:   Thu, 19 Mar 2020 19:01:53 -0700
Message-Id: <20200319190144.1.I40cc9b3d5de04f0631c931d94757fb0f462b24bd@changeid>
In-Reply-To: <20200320020153.98280-1-abhishekpandit@chromium.org>
References: <20200320020153.98280-1-abhishekpandit@chromium.org>
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Sender: linux-bluetooth-owner@vger.kernel.org
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From: Matthias Kaehlcke <mka@chromium.org>

When scanning for BLE devices for a longer period (e.g. because a
BLE device is paired, but not connected) the Marvell 8997 often
ends up in a borked state, which manifests through failures on
certain SDIO transactions.

When such a SDIO failure is detected force a reset of the SDIO
card to initialize it from scratch. Since the SDIO bus is shared
with the WiFi part of the chip this also involves a reset of WiFi.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

 drivers/bluetooth/btmrvl_sdio.c | 24 ++++++++++++++++++++++++
 drivers/bluetooth/btmrvl_sdio.h |  1 +
 2 files changed, 25 insertions(+)

diff --git a/drivers/bluetooth/btmrvl_sdio.c b/drivers/bluetooth/btmrvl_sdio.c
index 0f3a020703ab..69a8b6b3c11c 100644
--- a/drivers/bluetooth/btmrvl_sdio.c
+++ b/drivers/bluetooth/btmrvl_sdio.c
@@ -22,6 +22,8 @@
 #include <linux/slab.h>
 #include <linux/suspend.h>
 
+#include <linux/mmc/core.h>
+#include <linux/mmc/card.h>
 #include <linux/mmc/sdio_ids.h>
 #include <linux/mmc/sdio_func.h>
 #include <linux/module.h>
@@ -59,6 +61,23 @@ static const struct of_device_id btmrvl_sdio_of_match_table[] = {
 	{ }
 };
 
+static void btmrvl_sdio_card_reset_work(struct work_struct *work)
+{
+	struct btmrvl_sdio_card *card =
+		container_of(work, struct btmrvl_sdio_card, reset_work);
+	struct sdio_func *func = card->func;
+
+	sdio_claim_host(func);
+	mmc_hw_reset(func->card->host);
+	sdio_release_host(func);
+}
+
+static void btmrvl_sdio_card_reset(struct btmrvl_sdio_card *card)
+{
+	BT_ERR("resetting SDIO card!");
+	schedule_work(&card->reset_work);
+}
+
 static irqreturn_t btmrvl_wake_irq_bt(int irq, void *priv)
 {
 	struct btmrvl_sdio_card *card = priv;
@@ -774,6 +793,7 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private *priv)
 	ret = btmrvl_sdio_read_rx_len(card, &buf_len);
 	if (ret < 0) {
 		BT_ERR("read rx_len failed");
+		btmrvl_sdio_card_reset(card);
 		ret = -EIO;
 		goto exit;
 	}
@@ -809,6 +829,7 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private *priv)
 			  num_blocks * blksz);
 	if (ret < 0) {
 		BT_ERR("readsb failed: %d", ret);
+		btmrvl_sdio_card_reset(card);
 		ret = -EIO;
 		goto exit;
 	}
@@ -913,6 +934,7 @@ static int btmrvl_sdio_read_to_clear(struct btmrvl_sdio_card *card, u8 *ireg)
 	ret = sdio_readsb(card->func, adapter->hw_regs, 0, SDIO_BLOCK_SIZE);
 	if (ret) {
 		BT_ERR("sdio_readsb: read int hw_regs failed: %d", ret);
+		btmrvl_sdio_card_reset(card);
 		return ret;
 	}
 
@@ -1591,6 +1613,8 @@ static int btmrvl_sdio_probe(struct sdio_func *func,
 		card->supports_fw_dump = data->supports_fw_dump;
 	}
 
+	INIT_WORK(&card->reset_work, btmrvl_sdio_card_reset_work);
+
 	if (btmrvl_sdio_register_dev(card) < 0) {
 		BT_ERR("Failed to register BT device!");
 		return -ENODEV;
diff --git a/drivers/bluetooth/btmrvl_sdio.h b/drivers/bluetooth/btmrvl_sdio.h
index 3a522d23ee6e..d35a2f1b7046 100644
--- a/drivers/bluetooth/btmrvl_sdio.h
+++ b/drivers/bluetooth/btmrvl_sdio.h
@@ -103,6 +103,7 @@ struct btmrvl_sdio_card {
 	struct btmrvl_private *priv;
 	struct device_node *plt_of_node;
 	struct btmrvl_plt_wake_cfg *plt_wake_cfg;
+	struct work_struct reset_work;
 };
 
 struct btmrvl_sdio_device {
-- 
2.25.1.696.g5e7596f4ac-goog