Received-SPF: pass (google.com: domain of linux-bluetooth-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue,  4 Oct 2022 17:47:14 +0800
Mime-Version: 1.0
Message-ID: <20221004174632.v2.1.I46e98b47be875d0b9abff2d19417c612077d1909@changeid>
Subject: [PATCH v2] 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>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
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 v2:
* Update commit message

 drivers/bluetooth/btusb.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 271963805a38..11040124ef79 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -696,6 +696,19 @@ struct btusb_data {
 	unsigned cmd_timeout_cnt;
 };
 
+static void generic_usb_reset(struct hci_dev *hdev, struct btusb_data *data)
+{
+	int err;
+
+	bt_dev_err(hdev, "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: %d", err);
+}
+
 static void btusb_intel_cmd_timeout(struct hci_dev *hdev)
 {
 	struct btusb_data *data = hci_get_drvdata(hdev);
@@ -705,7 +718,7 @@ 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");
+		generic_usb_reset(hdev, data);
 		return;
 	}
 
@@ -736,7 +749,7 @@ 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");
+		generic_usb_reset(hdev, data);
 		return;
 	}
 
@@ -761,7 +774,6 @@ 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 +799,7 @@ 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);
+	generic_usb_reset(hdev, data);
 }
 
 static inline void btusb_free_frags(struct btusb_data *data)
-- 
2.38.0.rc1.362.ged0d419d3c-goog