From b4a46996f1d21c23269cc6b989e4db22ce69061f Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 29 Jun 2021 21:59:07 +0200 Subject: Bluetooth: hci_h5: Disable the hci_suspend_notifier for btrtl devices The hci_suspend_notifier which was introduced last year, is causing problems for uart attached btrtl devices. These devices may loose their firmware and their baudrate setting over a suspend/resume. Since we don't even know the baudrate after a suspend/resume recovering from this is tricky. The driver solves this by treating these devices the same as USB BT HCIs which drop of the bus during suspend. Specifically the driver: 1. Simply unconditionally turns the device fully off during system-suspend to save maximum power. 2. Calls device_reprobe() from a workqueue to fully re-init the device from scratch on system-resume (unregistering the old HCI and registering a new HCI). This means that these devices do not benefit from the suspend / resume handling work done by the hci_suspend_notifier. At best this unnecessarily adds some time to the suspend/resume time. But in practice this is actually causing problems: 1. These btrtl devices seem to not like the HCI_OP_WRITE_SCAN_ENABLE( SCAN_DISABLED) request being send to them when entering the BT_SUSPEND_CONFIGURE_WAKE state. The same request send on BT_SUSPEND_DISCONNECT works fine, but the second one send (unnecessarily?) from the BT_SUSPEND_CONFIGURE_WAKE transition causes the device to hang: [ 573.497754] PM: suspend entry (s2idle) [ 573.554615] Filesystems sync: 0.056 seconds [ 575.837753] Bluetooth: hci0: Timed out waiting for suspend events [ 575.837801] Bluetooth: hci0: Suspend timeout bit: 4 [ 575.837925] Bluetooth: hci0: Suspend notifier action (3) failed: -110 2. The PM_POST_SUSPEND / BT_RUNNING transition races with the driver-unbinding done by the device_reprobe() work. If the hci_suspend_notifier wins the race it is talking to a dead device leading to the following errors being logged: [ 598.686060] Bluetooth: hci0: Timed out waiting for suspend events [ 598.686124] Bluetooth: hci0: Suspend timeout bit: 5 [ 598.686237] Bluetooth: hci0: Suspend notifier action (4) failed: -110 In both cases things still work, but the suspend-notifier is causing these ugly errors getting logged and ut increase both the suspend- and the resume-time by 2 seconds. This commit avoids these problems by disabling the hci_suspend_notifier. Cc: Luiz Augusto von Dentz Cc: Vasily Khoruzhick Cc: Abhishek Pandit-Subedi Signed-off-by: Hans de Goede Signed-off-by: Marcel Holtmann --- drivers/bluetooth/hci_h5.c | 7 +++++++ drivers/bluetooth/hci_serdev.c | 3 +++ drivers/bluetooth/hci_uart.h | 7 ++++--- 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c index e0520639f4ba..7b985c7cd26d 100644 --- a/drivers/bluetooth/hci_h5.c +++ b/drivers/bluetooth/hci_h5.c @@ -916,6 +916,13 @@ out_free: static void h5_btrtl_open(struct h5 *h5) { + /* + * Since h5_btrtl_resume() does a device_reprobe() the suspend handling + * done by the hci_suspend_notifier is not necessary; it actually causes + * delays and a bunch of errors to get logged, so disable it. + */ + set_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &h5->hu->flags); + /* Devices always start with these fixed parameters */ serdev_device_set_flow_control(h5->hu->serdev, false); serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN); diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c index 9e03402ef1b3..3b00d82d36cf 100644 --- a/drivers/bluetooth/hci_serdev.c +++ b/drivers/bluetooth/hci_serdev.c @@ -343,6 +343,9 @@ int hci_uart_register_device(struct hci_uart *hu, hdev->setup = hci_uart_setup; SET_HCIDEV_DEV(hdev, &hu->serdev->dev); + if (test_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &hu->flags)) + set_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks); + if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags)) set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks); diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h index 4e039d7a16f8..fb4a2d0d8cc8 100644 --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -86,9 +86,10 @@ struct hci_uart { }; /* HCI_UART proto flag bits */ -#define HCI_UART_PROTO_SET 0 -#define HCI_UART_REGISTERED 1 -#define HCI_UART_PROTO_READY 2 +#define HCI_UART_PROTO_SET 0 +#define HCI_UART_REGISTERED 1 +#define HCI_UART_PROTO_READY 2 +#define HCI_UART_NO_SUSPEND_NOTIFIER 3 /* TX states */ #define HCI_UART_SENDING 1 -- cgit v1.2.3-59-g8ed1b