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Date:   Thu,  6 Oct 2022 17:09:31 +0800
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Message-ID: <20221006170915.v3.1.I46e98b47be875d0b9abff2d19417c612077d1909@changeid>
Subject: [PATCH v3] Bluetooth: btusb: Introduce generic USB reset
From:   Archie Pusaka <apusaka@google.com>
To:     linux-bluetooth <linux-bluetooth@vger.kernel.org>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        Marcel Holtmann <marcel@holtmann.org>
Cc:     CrosBT Upstreaming <chromeos-bluetooth-upstreaming@chromium.org>,
        Archie Pusaka <apusaka@chromium.org>,
        Abhishek Pandit-Subedi <abhishekpandit@google.com>,
        Ying Hsu <yinghsu@chromium.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
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Precedence: bulk

From: Archie Pusaka <apusaka@chromium.org>

On cmd_timeout with no reset_gpio, reset the USB port as a last
resort.

This patch changes the behavior of btusb_intel_cmd_timeout and
btusb_rtl_cmd_timeout.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@google.com>
Reviewed-by: Ying Hsu <yinghsu@chromium.org>

---
Tested by not cancelling cmd_timer when handing hci event.
Before the patch:
ERR kernel: [  716.929206] Bluetooth: hci_cmd_timeout() hci0: command 0x0000 tx timeout
ERR kernel: [  716.929218] Bluetooth: btusb_rtl_cmd_timeout() hci0: No gpio to reset Realtek device, ignoring

After the patch:
ERR kernel: [  225.270048] Bluetooth: hci_cmd_timeout() hci0: command 0x0000 tx timeout
ERR kernel: [  225.270060] Bluetooth: btusb_rtl_cmd_timeout() hci0: Resetting usb device.
INFO kernel: [  225.386613] usb 3-3: reset full-speed USB device number 3 using xhci_hcd

Changes in v3:
* introduce hdev->reset to override the generic reset function

Changes in v2:
* Update commit message

 drivers/bluetooth/btusb.c        | 35 +++++++++++++++++++++++---------
 include/net/bluetooth/hci_core.h |  1 +
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 271963805a38..e6add3604214 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -696,6 +696,28 @@ struct btusb_data {
 	unsigned cmd_timeout_cnt;
 };
 
+static void btusb_reset(struct hci_dev *hdev)
+{
+	struct btusb_data *data;
+	int err;
+
+	if (hdev->reset) {
+		hdev->reset(hdev);
+		return;
+	}
+
+	data = hci_get_drvdata(hdev);
+	/* This is not an unbalanced PM reference since the device will reset */
+	err = usb_autopm_get_interface(data->intf);
+	if (err) {
+		bt_dev_err(hdev, "Failed usb_autopm_get_interface: %d", err);
+		return;
+	}
+
+	bt_dev_err(hdev, "Resetting usb device.");
+	usb_queue_reset_device(data->intf);
+}
+
 static void btusb_intel_cmd_timeout(struct hci_dev *hdev)
 {
 	struct btusb_data *data = hci_get_drvdata(hdev);
@@ -705,7 +727,7 @@ static void btusb_intel_cmd_timeout(struct hci_dev *hdev)
 		return;
 
 	if (!reset_gpio) {
-		bt_dev_err(hdev, "No way to reset. Ignoring and continuing");
+		btusb_reset(hdev);
 		return;
 	}
 
@@ -736,7 +758,7 @@ static void btusb_rtl_cmd_timeout(struct hci_dev *hdev)
 		return;
 
 	if (!reset_gpio) {
-		bt_dev_err(hdev, "No gpio to reset Realtek device, ignoring");
+		btusb_reset(hdev);
 		return;
 	}
 
@@ -761,7 +783,6 @@ static void btusb_qca_cmd_timeout(struct hci_dev *hdev)
 {
 	struct btusb_data *data = hci_get_drvdata(hdev);
 	struct gpio_desc *reset_gpio = data->reset_gpio;
-	int err;
 
 	if (++data->cmd_timeout_cnt < 5)
 		return;
@@ -787,13 +808,7 @@ static void btusb_qca_cmd_timeout(struct hci_dev *hdev)
 		return;
 	}
 
-	bt_dev_err(hdev, "Multiple cmd timeouts seen. Resetting usb device.");
-	/* This is not an unbalanced PM reference since the device will reset */
-	err = usb_autopm_get_interface(data->intf);
-	if (!err)
-		usb_queue_reset_device(data->intf);
-	else
-		bt_dev_err(hdev, "Failed usb_autopm_get_interface with %d", err);
+	btusb_reset(hdev);
 }
 
 static inline void btusb_free_frags(struct btusb_data *data)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index c54bc71254af..55a40f5606c3 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -659,6 +659,7 @@ struct hci_dev {
 	int (*set_diag)(struct hci_dev *hdev, bool enable);
 	int (*set_bdaddr)(struct hci_dev *hdev, const bdaddr_t *bdaddr);
 	void (*cmd_timeout)(struct hci_dev *hdev);
+	void (*reset)(struct hci_dev *hdev);
 	bool (*wakeup)(struct hci_dev *hdev);
 	int (*set_quality_report)(struct hci_dev *hdev, bool enable);
 	int (*get_data_path_id)(struct hci_dev *hdev, __u8 *data_path);
-- 
2.38.0.rc1.362.ged0d419d3c-goog