Re: [PATCH v5 1/2] firmware: qcom: scm: Register gunyah watchdog device

[Hrishabh Rajput <hrishabh.rajput@oss.qualcomm.com>]

On 11/11/2025 5:52 PM, Dmitry Baryshkov wrote:
> On Tue, Nov 11, 2025 at 11:41:51AM +0100, Krzysztof Kozlowski wrote:
>> On 11/11/2025 11:34, Dmitry Baryshkov wrote:
>>> On Tue, Nov 11, 2025 at 10:51:43AM +0530, Pavan Kondeti wrote:
>>>> On Mon, Nov 10, 2025 at 09:43:53AM +0530, Pavan Kondeti wrote:
>>>>> On Sat, Nov 08, 2025 at 07:26:46PM +0200, Dmitry Baryshkov wrote:
>>>>>>> +static void qcom_scm_gunyah_wdt_free(void *data)
>>>>>>> +{
>>>>>>> +	struct platform_device *gunyah_wdt_dev = data;
>>>>>>> +
>>>>>>> +	platform_device_unregister(gunyah_wdt_dev);
>>>>>>> +}
>>>>>>> +
>>>>>>> +static void qcom_scm_gunyah_wdt_init(struct qcom_scm *scm)
>>>>>>> +{
>>>>>>> +	struct platform_device *gunyah_wdt_dev;
>>>>>>> +	struct device_node *np;
>>>>>>> +	bool of_wdt_available;
>>>>>>> +	int i;
>>>>>>> +	uuid_t gunyah_uuid = UUID_INIT(0xc1d58fcd, 0xa453, 0x5fdb, 0x92, 0x65,
>>>>>> static const?
>>>>>>
>>>>>>> +				       0xce, 0x36, 0x67, 0x3d, 0x5f, 0x14);
>>>>>>> +	static const char * const of_wdt_compatible[] = {
>>>>>>> +		"qcom,kpss-wdt",
>>>>>>> +		"arm,sbsa-gwdt",
>>>>>>> +	};
>>>>>>> +
>>>>>>> +	/* Bail out if we are not running under Gunyah */
>>>>>>> +	if (!arm_smccc_hypervisor_has_uuid(&gunyah_uuid))
>>>>>>> +		return;
>>>>>> This rquires 'select HAVE_ARM_SMCCC_DISCOVERY'
>>>>>>
>>>>> Probably `depends on HAVE_ARM_SMCCC_DISCOVERY` is correct here.
>>>>>
>>>> Dmitry / Bjorn,
>>>>
>>>> We are debating on this internally on how to resolve this dependency
>>>>
>>>> - QCOM_SCM depends on HAVE_ARM_SMCCC_DISCOVERY which means restricting
>>>>    QCOM_SCM compilation than what it is today.
>>>>
>>>> - Adding #ifdefry around arm_smccc_hypervisor_has_uuid usage in qcom scm driver
>>>>
>>>> - Adding stub for `arm_smccc_hypervisor_has_uuid()` which is not done
>>>>    for any of the functions defined in drivers/firmware/smccc/smccc.c
>>>>
>>>> We are trending towards the first option above. Please let us know if
>>>> you think otherwise.
>>> The same as before: 'select HAVE_ARM_SMCCC_DISCOVERY'.
>> HAVE_ARM_SMCCC_DISCOVERY has a dependency which is not always selected
>> (e.g. ARM32), thus selecting it might lead to warnings of unmet
>> dependencies.
> Then `if (!IS_ENABLED(CONFIG_HAVE_ARM_SMCCC_DISCOVERY))` might be a good
> option here (and depend on GICv3 selecting it).


Thanks a lot Dmitry, wemade the change below and compile tested on 
various architectures (ARM64, ARM32, x86, PowerPC, RISC-V and MIPS) and 
it was success.

We will include it in our next patch version, if there are no further 
concerns.

}; /* Bail out if we are not running under Gunyah */ - if 
(!arm_smccc_hypervisor_has_uuid(&gunyah_uuid)) + if 
(!IS_ENABLED(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) || + 
!arm_smccc_hypervisor_has_uuid(&gunyah_uuid)) return; /*

Thanks,

Hrishabh