Re: [PATCH v1] serial: qcom_geni: Fix BT failure regression on RB2 platform

[Praveen Talari]

Hi Dmistry,

On 1/7/2026 12:24 PM, Dmitry Baryshkov wrote:
> On Wed, 7 Jan 2026 at 08:48, Praveen Talari
> <praveen.talari@xxxxxxxxxxxxxxxx> wrote:
> > A regression in linux-next causes Bluetooth functionality to fail during
>
> linux-next is an ephemeral thing. Please reference the exact commit.
>
> > bootup on the RB2 platform, preventing proper BT initialization. However,
> > BT works correctly after bootup completes.
> >
> > The issue occurs when runtime PM is enabled and uart_add_one_port() is
> > called before wakeup IRQ setup. The uart_add_one_port() call activates the
> > device through runtime PM, which configures GPIOs to their default state.
> > When wakeup IRQ registration happens afterward, it conflicts with these
> > GPIO settings, causing state corruption that breaks Bluetooth
> > functionality.
>
> How does it "conflict with GPIO settings", what is "state corruption"?

I mean the issue occurs because the GPIO state is being altered during 
the wakeup source registration process..

Thanks,
Praveen Talari
> > Fix this by moving runtime PM enablement and uart_add_one_port() after
> > wakeup IRQ registration, ensuring proper initialization order.
> >
> > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
> > Closes:
> > https://lore.kernel.org/all/20251110101043.2108414-4-praveen.talari@xxxxxxxxxxxxxxxx/
> > Fixes: 10904d725f6e ("serial: qcom-geni: Enable PM runtime for serial driver")
> > Signed-off-by: Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/tty/serial/qcom_geni_serial.c | 12 ++++++------
> >   1 file changed, 6 insertions(+), 6 deletions(-)
>
> Tested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>