Re: [PATCH v1 3/4] serial: qcom-geni: Enable PM runtime for serial driver

[Praveen Talari <praveen.talari@oss.qualcomm.com>]

Hi Dmitry,

On 12/31/2025 11:21 AM, Dmitry Baryshkov wrote:
> On 31/12/2025 07:49, Praveen Talari wrote:
>> Hi Dmitry,
>>
>> On 12/31/2025 8:30 AM, Dmitry Baryshkov wrote:
>>> On 31/12/2025 05:00, Praveen Talari wrote:
>>>> Hi Dmitry,
>>>>
>>>> On 12/30/2025 11:53 PM, Dmitry Baryshkov wrote:
>>>>> On Mon, Nov 10, 2025 at 03:40:42PM +0530, Praveen Talari wrote:
>>>>>> The GENI serial driver currently handles power resource management
>>>>>> through calls to the statically defined geni_serial_resources_on() 
>>>>>> and
>>>>>> geni_serial_resources_off() functions. This approach reduces 
>>>>>> modularity
>>>>>> and limits support for platforms with diverse power management
>>>>>> mechanisms, including resource managed by firmware.
>>>>>>
>>>>>> Improve modularity and enable better integration with platform- 
>>>>>> specific
>>>>>> power management, introduce support for runtime PM. Use
>>>>>> pm_runtime_resume_and_get() and pm_runtime_put_sync() within the
>>>>>> qcom_geni_serial_pm() callback to control resource power state
>>>>>> transitions based on UART power state changes.
>>>>>>
>>>>>> Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
>>>>>> ---
>>>>>>   drivers/tty/serial/qcom_geni_serial.c | 24 ++++++++++++++++++++++--
>>>>>>   1 file changed, 22 insertions(+), 2 deletions(-)
>>>>>>
>>>>>
>>>>> This breaks BT support on the Qualcomm RB2 platform. With this patch
>>>>> applied, I'm getting the following:
>>>>>
>>>>> root@qcom-armv8a:~# dmesg | grep tty\\\|hci0
>>>>> [    0.000000] Kernel command line:  ignore_loglevel 
>>>>> console=ttyMSM0,115200n8 earlycon root=PARTLABEL=rootfs rootwait 
>>>>> systemd.mask=pd-mapper.service -- 
>>>>> androidboot.bootdevice=4744000.sdhci androidboot.serialno=2b89b520 
>>>>> androidboot.baseband=apq 
>>>>> msm_drm.dsi_display0=qcom,mdss_dsi_ext_bridge_1080p:
>>>>> [    4.074354] 4a8c000.serial: ttyHS1 at MMIO 0x4a8c000 (irq = 140, 
>>>>> base_baud = 0) is a MSM
>>>>> [    4.099410] serial serial0: tty port ttyHS1 registered
>>>>> [    4.131200] Bluetooth: hci0: setting up wcn399x
>>>>> [    4.149847] 4a90000.serial: ttyMSM0 at MMIO 0x4a90000 (irq = 
>>>>> 142, base_baud = 0) is a MSM
>>>>> [    4.229099] printk: legacy console [ttyMSM0] enabled
>>>>> [    6.499519] Bluetooth: hci0: command 0xfc00 tx timeout
>>>>> [    6.514347] Bluetooth: hci0: Reading QCA version information 
>>>>> failed (-110)
>>>>> [    6.559933] Bluetooth: hci0: Retry BT power ON:0
>>>>> [    8.016330] systemd[1]: Created slice Slice /system/getty.
>>>>> [    8.066194] systemd[1]: Created slice Slice /system/serial-getty.
>>>>> [    8.148389] systemd[1]: Expecting device /dev/ttyMSM0...
>>>>> [    8.956804] Bluetooth: hci0: command 0xfc00 tx timeout
>>>>> [    8.962447] Bluetooth: hci0: Reading QCA version information 
>>>>> failed (-110)
>>>>> [    8.976917] Bluetooth: hci0: Retry BT power ON:1
>>>>> [   11.296715] Bluetooth: hci0: command 0xfc00 tx timeout
>>>>> [   11.302340] Bluetooth: hci0: Reading QCA version information 
>>>>> failed (-110)
>>>>> [   11.309534] Bluetooth: hci0: Retry BT power ON:2
>>>>> [   13.660078] Bluetooth: hci0: command 0xfc00 tx timeout
>>>>> [   13.665814] Bluetooth: hci0: Reading QCA version information 
>>>>> failed (-110)
>>>>
>>>> Sure, will check and update.
>>>>
>>>> If possible, can you share what is DT filename for RB2.
>>>
>>> qrb4210-rb2.dts
>>
>> Can you please try below change on target since i didn't get target yet?
> 
> Yes, I have this patch too. It didn't help.

As we discussed offline, On the RB2 target, Bluetooth fails during 
bootup but functions correctly once bootup is complete.

I suspect that GPIO configurations are being affected during the bootup 
process, possibly due to the wakeup registration sequence.

To address this, I have moved the wakeup registration process to occur 
before enabling PM runtime.

Could you please try below change and let me know result?

diff --git a/drivers/tty/serial/qcom_geni_serial.c 
b/drivers/tty/serial/qcom_geni_serial.c
index 6ce6528f5c10..46a9c71630d5 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1888,12 +1888,6 @@ static int qcom_geni_serial_probe(struct 
platform_device *pdev)
         if (ret)
                 goto error;

-       devm_pm_runtime_enable(port->se.dev);
-
-       ret = uart_add_one_port(drv, uport);
-       if (ret)
-               goto error;
-
         if (port->wakeup_irq > 0) {
                 device_init_wakeup(&pdev->dev, true);
                 ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
@@ -1906,6 +1900,12 @@ static int qcom_geni_serial_probe(struct 
platform_device *pdev)
                 }
         }

+       devm_pm_runtime_enable(port->se.dev);
+
+       ret = uart_add_one_port(drv, uport);
+       if (ret)
+               goto error;
+
         return 0;

Thanks,
Praveen Talari
> 
>>
>> diff --git a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts b/arch/arm64/ 
>> boot/ dts/qcom/qrb4210-rb2.dts
>> index 0cd36c54632f..5f8613150bdd 100644
>> --- a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
>> +++ b/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
>> @@ -694,7 +694,7 @@ sdc2_card_det_n: sd-card-det-n-state {
>>
>>   &uart3 {
>>          interrupts-extended = <&intc GIC_SPI 330 IRQ_TYPE_LEVEL_HIGH>,
>> -                             <&tlmm 11 IRQ_TYPE_LEVEL_HIGH>;
>> +                             <&tlmm 11 IRQ_TYPE_EDGE_FALLING>;
>>          pinctrl-0 = <&uart3_default>;
>>          pinctrl-1 = <&uart3_sleep>;
>>          pinctrl-names = "default", "sleep";
>>
>> Thanks,
>> Praveen Talari
>>
>>>
>>>>
>>>> Earlier I had validated on RB1 and Kodiak.
>>>>
>>>> Thanks,
>>>> Praveen
>>>>
>>>>>
>>>>> After reverting the next and this patches, BT is back to normal:
>>>>>
>>>>> [    4.067201] 4a8c000.serial: ttyHS1 at MMIO 0x4a8c000 (irq = 140, 
>>>>> base_baud = 0) is a MSM
>>>>> [    4.082426] serial serial0: tty port ttyHS1 registered
>>>>> [    4.106122] 4a90000.serial: ttyMSM0 at MMIO 0x4a90000 (irq = 
>>>>> 142, base_baud = 0) is a MSM
>>>>> [    4.108647] Bluetooth: hci0: setting up wcn399x
>>>>> [    4.125371] printk: legacy console [ttyMSM0] enabled
>>>>> [    4.445205] Bluetooth: hci0: QCA Product ID   :0x0000000a
>>>>> [    4.450927] Bluetooth: hci0: QCA SOC Version  :0x40020150
>>>>> [    4.456470] Bluetooth: hci0: QCA ROM Version  :0x00000201
>>>>> [    4.462006] Bluetooth: hci0: QCA Patch Version:0x00000001
>>>>> [    4.509408] Bluetooth: hci0: QCA controller version 0x01500201
>>>>> [    4.515656] Bluetooth: hci0: QCA Downloading qca/apbtfw11.tlv
>>>>> [    5.488739] Bluetooth: hci0: QCA Downloading qca/apnv11.bin
>>>>> [    5.671740] Bluetooth: hci0: QCA setup on UART is completed
>>>>> [    7.993368] systemd[1]: Created slice Slice /system/getty.
>>>>> [    8.045612] systemd[1]: Created slice Slice /system/serial-getty.
>>>>> [    8.125418] systemd[1]: Expecting device /dev/ttyMSM0...
>>>>>
>>>>>
>>>
>>>
>>
> 
>