platform/x86/amd: pmc: Read SMU version during suspend on Cezanne systems

commit b0c07116c8 ("platform/x86: amd-pmc: Avoid reading SMU version at
probe time") adjusted the behavior for amd-pmc to avoid reading the SMU
version at startup but rather on first use to improve boot time.

However the SMU version is also used to decide whether to place a timer
based wakeup in the OS_HINT message. If the idlemask hasn't been read
before this message was sent then the SMU version will not have been
cached.

Ensure the SMU version has been read before deciding whether or not to
run this codepath.

Cc: stable@vger.kernel.org # 6.0
Reported-by: You-Sheng Yang <vicamo.yang@canonical.com>
Tested-by: Anson Tsao <anson.tsao@amd.com>
Fixes: b0c07116c8 ("platform/x86: amd-pmc: Avoid reading SMU version at probe time")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20221020113749.6621-2-mario.limonciello@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/amd/pmc.c

@@ -663,6 +663,13 @@ static int amd_pmc_verify_czn_rtc(struct amd_pmc_dev *pdev, u32 *arg)
 	struct rtc_time tm;
 	int rc;
 
+	/* we haven't yet read SMU version */
+	if (!pdev->major) {
+		rc = amd_pmc_get_smu_version(pdev);
+		if (rc)
+			return rc;
+	}
+
 	if (pdev->major < 64 || (pdev->major == 64 && pdev->minor < 53))
 		return 0;