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

[Dmitry Baryshkov]

On Wed, Jan 07, 2026 at 04:28:22PM +0530, Praveen Talari wrote:
> Hi Konrad,
> 
> On 1/7/2026 4:16 PM, Konrad Dybcio wrote:
> > On 1/7/26 10:24 AM, Praveen Talari wrote:
> > > Hi
> > > 
> > > On 1/7/2026 12:52 PM, Dmitry Baryshkov wrote:
> > > > On Wed, 7 Jan 2026 at 09:06, Praveen Talari
> > > > <praveen.talari@xxxxxxxxxxxxxxxx> wrote:
> > > > > 
> > > > > 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..
> > > > 
> > > > Altered how?
> > > 
> > > During the runtime resume of devices, GPIOs are configured to QUP mode. However, when registering the wakeup IRQ using dev_pm_set_dedicated_wake_irq(), these GPIOs are reset back to FUNC mode, which impacts the RX GPIO and leads to Bluetooth failures
> > 
> > "QUP mode" and "FUNC mode" are tough to swallow even for an insider.. How
> > about:
> > 
> > "qup_x" and "gpio" pinmux functions
> 
> Yes, you are right. I am talking about "qup_x" and "gpio" pinmux functions

=> commit message, please.

> 
> Thanks,
> Praveen Talari
> > 
> > ?
> > 
> > Konrad
> 

-- 
With best wishes
Dmitry