Hi Heikki, Andy, Greg, Rafael,
I've detected a regression on my Lenovo ThinkPad 8 tablet introduced during
4.9-rc1, preventing the built-in Bluetooth Broadcom chipset from properly
initializing, with many timeout messages in dmesg like these:
"serial8250_interrupt: WXYZ callbacks suppressed"
"serial8250: too much work for irq39"
cf. my earlier report on linux-bluetooth at the very end for reference.
After a long git bisect, I've found the commit that's triggering the issue:
commit 20a875e2e86e73d13ec256781a7d55a7885868ec
Author: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Date: Tue Aug 23 11:33:28 2016 +0300
serial: 8250_dw: Add quirk for APM X-Gene SoC
The APM X-Gene SoC UART is the only board that still needs
the hard-coded values, so handle it separately in
dw8250_quirks(). The other ACPI platforms are able to
provide the values with device properties.
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
diff --git a/drivers/tty/serial/8250/8250_dw.c
b/drivers/tty/serial/8250/8250_dw.c
index e199696..5c0c123 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -298,12 +298,17 @@ static void dw8250_quirks(struct uart_port *p, struct
dw8250_data *data)
p->serial_out = dw8250_serial_out32be;
}
} else if (has_acpi_companion(p->dev)) {
- p->iotype = UPIO_MEM32;
- p->regshift = 2;
- p->serial_in = dw8250_serial_in32;
+ const struct acpi_device_id *id;
+
+ id = acpi_match_device(p->dev->driver->acpi_match_table,
+ p->dev);
+ if (id && !strcmp(id->id, "APMC0D08")) {
+ p->iotype = UPIO_MEM32;
+ p->regshift = 2;
+ p->serial_in = dw8250_serial_in32;
+ data->uart_16550_compatible = true;
+ }
p->set_termios = dw8250_set_termios;
- /* So far none of there implement the Busy Functionality */
- data->uart_16550_compatible = true;
}
/* Platforms with iDMA */
This is fully reproducible on my end: removing this specific patch gets rid
of the issue; with the patch applied, Bluetooth simply doesn't work anymore.
As opposed to the commit description, it seems that the Lenovo ThinkPad 8
still needs the original hard-coded values currently (even if it could be
possible to provide them in another way in the future, if I interpret the
commit message the right way).
Could this patch be reverted for the moment to remove the regression, until
a proper fix is found?
Thanks,
Jérôme
> I've compiled the latest bluetooth-next branch and I'm facing what looks
> like a regression to me (still on a Lenovo ThinkPad 8 tablet): btattach
> doesn't properly initialize the Broadcom BCM2E55 chipset anymore.
>
> I'm getting various timeout messages in dmesg:
>
> [ 13.188057] Bluetooth: hci0 command 0xfc45 tx timeout
> [ 16.093068] serial8250_interrupt: 4158 callbacks suppressed
> [ 16.093072] serial8250: too much work for irq39
> [ 16.094287] serial8250: too much work for irq39
> ...
> [ 16.103868] serial8250: too much work for irq39
> [ 21.100041] serial8250_interrupt: 4167 callbacks suppressed
> [ 21.100044] serial8250: too much work for irq39
> ...
> [ 21.222065] Bluetooth: hci0: BCM: failed to write clock (-110)
> [ 23.238528] Bluetooth: hci0 command 0x0c03 tx timeout
> [ 26.104253] serial8250_interrupt: 4165 callbacks suppressed
> [ 26.104257] serial8250: too much work for irq39
>
> which I never had before and Bluetooth never actually starts.
>
> Bluetooth doesn't init with a kernel built with the latest commit from
> yesterday 526c86021e5102b8a4b5555b4196f7a19f44e2c4.
>
> I've gone back in time and it doesn't work either with a kernel built at
> e6445f52d9c8b0e6557a45fa7d0e8e088d430a8c "Merge tag 'usb-4.9-rc1' of
> git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb".
>
> It still worked at commit a2f195a73eba807006fb0cb882ecb552c06eea00
> "bluetooth: bcm203x: don't print error when allocating urb fails" though,
> which was the last previous commit modifying files in drivers/bluetooth in
> the bluetooth-next branch.
>
> I've attached the output of btmon when it used to work and one not working
> (prefixed with .e6445f5) if that may be useful.
>
> I'll continue my investigation in my spare time, trying to bissect to find
> a while. I'll focus on patches touching the serial 8250 driver to start
> with, as there are only a few of them, but feel free to point me into a
> different direction if you have another idea or suggestion.
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