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

From: Hrishabh Rajput

Date: Tue Nov 11 2025 - 23:37:38 EST


On 11/11/2025 8:35 PM, Dmitry Baryshkov wrote:
On Tue, Nov 11, 2025 at 07:30:59PM +0530, Hrishabh Rajput wrote:
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; /*
Unreadable. Don't you read what you are sending?

Sorry, my mail client messed up the formatting while sending. Here is the proper version:

/* 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