platform/x86/amd: pmc: Add a workaround for an s0i3 issue on Cezanne

Cezanne platforms under the right circumstances have a synchronization
problem where attempting to enter s2idle may fail if the x86 cores are
put into HLT before hardware resume from the previous attempt has
completed.

To avoid this issue add a 10-20ms delay before entering s2idle another
time. This workaround will only be applied on interrupts that wake the
hardware but don't break the s2idle loop.

Cc: [email protected] # 6.1
Cc: "Mahapatra, Rajib" <[email protected]>
Cc: "Raul Rangel" <[email protected]>
Signed-off-by: Mario Limonciello <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

Author: superm1

drivers/platform/x86/amd/pmc.c

@@ -739,8 +739,14 @@ static void amd_pmc_s2idle_prepare(void)
 static void amd_pmc_s2idle_check(void)
 {
 	struct amd_pmc_dev *pdev = &pmc;
+	struct smu_metrics table;
 	int rc;
 
+	/* CZN: Ensure that future s0i3 entry attempts at least 10ms passed */
+	if (pdev->cpu_id == AMD_CPU_ID_CZN && !get_metrics_table(pdev, &table) &&
+	    table.s0i3_last_entry_status)
+		usleep_range(10000, 20000);
+
 	/* Dump the IdleMask before we add to the STB */
 	amd_pmc_idlemask_read(pdev, pdev->dev, NULL);