On Thu, Oct 28, 2021 at 12:23:26AM +0200, megi xff wrote: > Hello Archie, > > On Fri, Jul 23, 2021 at 07:31:57PM +0800, Archie Pusaka wrote: > > From: Archie Pusaka <apusaka@xxxxxxxxxxxx> > > > > This patch allows the controller to suspend after a short period of > > inactivity. > > I see this pattern in dmesg after this patch: (I've added printks > to many hci_h5 functions to see what's going on) > > [ 493.150325] h5_dequeue > [ 493.150332] h5_dequeue > [ 493.150336] h5_dequeue > [ 493.150340] h5_dequeue > [ 493.150370] h5_dequeue > [ 493.150547] h5_recv > [ 493.150863] h5_recv > [ 493.150878] h5_dequeue > [ 493.150885] h5_dequeue > [ 493.150888] h5_dequeue > [ 493.151315] h5_enqueue > [ 493.151328] h5_dequeue > [ 493.151350] h5_dequeue > [ 493.151447] h5_dequeue > [ 493.151612] h5_recv > [ 493.151945] h5_recv > [ 493.151961] h5_dequeue > [ 493.151967] h5_dequeue > [ 493.151970] h5_dequeue > [ 495.171812] h5_flush > [ 495.171845] h5_flush > [ 499.267473] h5_serdev_suspend > [ 499.267490] h5_btrtl_suspend > [ 499.273784] h5_recv > [ 499.273828] h5_serdev_resume > [ 499.273833] h5_btrtl_resume > [ 499.273837] h5_btrtl_resume / reprobe > [ 499.273855] h5_btrtl_reprobe_worker > [ 499.273913] h5_serdev_remove > [ 499.274997] h5_close > [ 499.275010] h5_btrtl_close > [ 499.275624] h5_serdev_probe > [ 499.276126] h5_open > [ 499.276132] h5_btrtl_open > [ 499.915820] h5_dequeue > [ 499.915857] h5_dequeue > [ 499.915863] h5_dequeue > [ 499.916212] h5_dequeue > [ 499.919643] h5_recv > [ 499.919675] h5_dequeue > [ 499.919682] h5_dequeue > [ 499.919687] h5_dequeue > [ 499.919692] h5_dequeue > > repeating ad nauseam every 6s. > > Basically bluetooth device reprobes every 6s. Looks like h5_recv call > after h5_btrtl_suspend wakes the device immediately after suspend. > > (there are no users of bluetooth in my userspace) I'd expect the > device to stay suspended after suspend. > > I have some extra patches to support 8723cs but nothing that > would affect this codepath. https://megous.com/git/linux/log/?h=bt-5.15 > > I assume it will have the same behavior with 8723bs which is already > mainline. I guess this issue is specific to devices with H5_INFO_WAKEUP_DISABLE > flag set. > > Do you have any ideas? I've added dump_stack() to first h5_recv call after suspend (the one that's causing the immediate wakeup after runtime PM suspend), and it returns: [ 5.938258] recv [ 13.377775] suspend [ 13.384106] recv [ 13.384120] CPU: 1 PID: 83 Comm: kworker/u8:1 Tainted: G C 5.15.0-rc7-00002-g64f2c49e8400 #23 [ 13.384141] Hardware name: Pine64 PinePhone (1.2) (DT) [ 13.384151] Workqueue: events_unbound flush_to_ldisc [ 13.384196] Call trace: [ 13.384199] dump_backtrace+0x0/0x15c [ 13.384224] show_stack+0x14/0x20 [ 13.384232] dump_stack_lvl+0x64/0x7c [ 13.384250] dump_stack+0x14/0x2c [ 13.384258] h5_recv+0x44/0xdbc [hci_uart] [ 13.384288] hci_uart_receive_buf+0x6c/0x94 [hci_uart] [ 13.384298] ttyport_receive_buf+0x60/0xf4 [ 13.384318] flush_to_ldisc+0xb0/0x160 [ 13.384324] process_one_work+0x1d8/0x380 [ 13.384339] worker_thread+0x178/0x4e0 [ 13.384348] kthread+0x11c/0x130 [ 13.384359] ret_from_fork+0x10/0x20 It's comming from here https://elixir.bootlin.com/linux/latest/source/drivers/tty/tty_buffer.c#L510 Which can be scheduled from these places: - https://elixir.bootlin.com/linux/latest/source/drivers/tty/tty_buffer.c#L65 - https://elixir.bootlin.com/linux/latest/source/drivers/tty/tty_buffer.c#L413 And that's where I lose a thread of what can be happening. :) Maybe h5_recv is not a good function to mark activity on the device, due to tty_buffer code just calling it to check if some data are available, even if none are? Even if nothing uses bluetooth from userspace... kind regards, o. > kind regards, > o. > > > > Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx> > > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> > > Reviewed-by: Hilda Wu <hildawu@xxxxxxxxxxx> > > > > --- > > > > Changes in v3: > > * Reordering #include > > > > drivers/bluetooth/hci_h5.c | 20 ++++++++++++++++++++ > > 1 file changed, 20 insertions(+) > > > > diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c > > index cbc63b057f33..0c0dedece59c 100644 > > --- a/drivers/bluetooth/hci_h5.c > > +++ b/drivers/bluetooth/hci_h5.c > > @@ -12,6 +12,7 @@ > > #include <linux/kernel.h> > > #include <linux/mod_devicetable.h> > > #include <linux/of_device.h> > > +#include <linux/pm_runtime.h> > > #include <linux/serdev.h> > > #include <linux/skbuff.h> > > > > @@ -21,6 +22,8 @@ > > #include "btrtl.h" > > #include "hci_uart.h" > > > > +#define SUSPEND_TIMEOUT_MS 6000 > > + > > #define HCI_3WIRE_ACK_PKT 0 > > #define HCI_3WIRE_LINK_PKT 15 > > > > @@ -584,6 +587,10 @@ static int h5_recv(struct hci_uart *hu, const void *data, int count) > > count -= processed; > > } > > > > + pm_runtime_get(&hu->serdev->dev); > > + pm_runtime_mark_last_busy(&hu->serdev->dev); > > + pm_runtime_put_autosuspend(&hu->serdev->dev); > > + > > return 0; > > } > > > > @@ -620,6 +627,10 @@ static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb) > > break; > > } > > > > + pm_runtime_get_sync(&hu->serdev->dev); > > + pm_runtime_mark_last_busy(&hu->serdev->dev); > > + pm_runtime_put_autosuspend(&hu->serdev->dev); > > + > > return 0; > > } > > > > @@ -951,6 +962,12 @@ static void h5_btrtl_open(struct h5 *h5) > > serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN); > > serdev_device_set_baudrate(h5->hu->serdev, 115200); > > > > + pm_runtime_set_active(&h5->hu->serdev->dev); > > + pm_runtime_use_autosuspend(&h5->hu->serdev->dev); > > + pm_runtime_set_autosuspend_delay(&h5->hu->serdev->dev, > > + SUSPEND_TIMEOUT_MS); > > + pm_runtime_enable(&h5->hu->serdev->dev); > > + > > /* The controller needs up to 500ms to wakeup */ > > gpiod_set_value_cansleep(h5->enable_gpio, 1); > > gpiod_set_value_cansleep(h5->device_wake_gpio, 1); > > @@ -959,6 +976,8 @@ static void h5_btrtl_open(struct h5 *h5) > > > > static void h5_btrtl_close(struct h5 *h5) > > { > > + pm_runtime_disable(&h5->hu->serdev->dev); > > + > > gpiod_set_value_cansleep(h5->device_wake_gpio, 0); > > gpiod_set_value_cansleep(h5->enable_gpio, 0); > > } > > @@ -1066,6 +1085,7 @@ MODULE_DEVICE_TABLE(acpi, h5_acpi_match); > > > > static const struct dev_pm_ops h5_serdev_pm_ops = { > > SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume) > > + SET_RUNTIME_PM_OPS(h5_serdev_suspend, h5_serdev_resume, NULL) > > }; > > > > static const struct of_device_id rtl_bluetooth_of_match[] = { > > -- > > 2.32.0.432.gabb21c7263-goog > >
