[PATCH v5 08/25] soundwire: amd: fix missing wake interrupt for ACP6.3 in POWER_OFF suspend

[Vijendar Mukunda]

On some OEM platforms based on ACP 6.3, with a SoundWire topology
where the UAJ peripheral is on one instance and the speaker peripheral
is on the other, wake events from the UAJ instance are silently lost
every time it enters POWER_OFF runtime suspend (D3) while speaker
playback keeps ACP in D0.

On ACP6.3, unlike ACP7.0/7.1/7.2, there is no dedicated host wake
interrupt path (no ACP_EXTERNAL_INTR_CNTL1 host wake mask bits and no
PME wake mechanism). The wake event from a suspended SoundWire instance
is delivered solely through the standard SoundWire interrupt bit in
ACP_EXTERNAL_INTR_CNTL.

In the POWER_OFF_MODE runtime suspend path, amd_deinit_sdw_manager()
calls amd_disable_sdw_interrupts() which clears the SoundWire instance
bit in ACP_EXTERNAL_INTR_CNTL. After this, the wake interrupt has no
delivery path to the CPU.

Fix this by re-enabling the SoundWire instance bit in
ACP_EXTERNAL_INTR_CNTL after amd_deinit_sdw_manager() and
amd_sdw_wake_enable() complete, when acp_rev is ACP63_PCI_REV_ID and
wake_en_mask is set. The acp_sdw_lock mutex is held around the
read-modify-write to prevent a race when both instances suspend or
resume concurrently.

Fixes: 86a4371b7697 ("soundwire: amd: fix for handling slave alerts after link is down")
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@xxxxxxx>
---
 drivers/soundwire/amd_manager.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
index 438cf52a212c..3f3fffbd529a 100644
--- a/drivers/soundwire/amd_manager.c
+++ b/drivers/soundwire/amd_manager.c
@@ -1467,6 +1467,13 @@ static int __maybe_unused amd_suspend_runtime(struct device *dev)
 			ret = amd_sdw_host_wake_enable(amd_manager, true);
 			if (ret)
 				return ret;
+		} else if ((amd_manager->acp_rev == ACP63_PCI_REV_ID) &&
+			   amd_manager->wake_en_mask) {
+			mutex_lock(amd_manager->acp_sdw_lock);
+			val = sdw_manager_reg_mask_array[amd_manager->instance];
+			amd_updatel(amd_manager->acp_mmio,
+				    ACP_EXTERNAL_INTR_CNTL(amd_manager->instance), val, val);
+			mutex_unlock(amd_manager->acp_sdw_lock);
 		}
 		/*
 		 * For ACP 7.0/7.1/7.2: disable OE only; keeper and schmen remain
-- 
2.53.0