[PATCH v5 22/25] soundwire: amd: fix interrupt gate and work drain ordering in PM ops

[Vijendar Mukunda <Vijendar.Mukunda@amd.com>]

The CLK_STOP_MODE branches in amd_suspend() and amd_suspend_runtime()
did not close the ACP_EXTERNAL_INTR_CNTL delivery gate before draining
amd_sdw_irq_thread and amd_sdw_work. An ISR already running when the
drains completed could re-queue work after cancel_work_sync() returned,
racing amd_sdw_clock_stop().

In both CLK_STOP_MODE paths, amd_sdw_wake_enable() was also called
before amd_enable_sdw_interrupts(). Since amd_enable_sdw_interrupts()
writes the interrupt mask unconditionally, it clobbered the wake bit
set by amd_sdw_wake_enable().

For both amd_suspend() and amd_suspend_runtime():
 - CLK_STOP_MODE: add amd_disable_sdw_interrupts() and
   cancel_work_sync(irq_thread) before the work drain; reopen the gate
   with amd_enable_sdw_interrupts() after clock stop, then call
   amd_sdw_wake_enable() so the wake bit is not clobbered.
 - POWER_OFF_MODE: add amd_disable_sdw_interrupts() and
   cancel_work_sync(irq_thread) before the work drain; remove the
   redundant post-clock-stop amd_disable_sdw_interrupts() call.

Fixes: 86a4371b7697 ("soundwire: amd: fix for handling slave alerts after link is down")
Reported-by: Lee Jones <lee@kernel.org>
Closes: https://sashiko.dev/#/bug/linux-3b774ace-00cf-41e6-82eb-85cd43f5e1d6
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
---
 drivers/soundwire/amd_manager.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
index 2b38b9bf97f5..4e151f7350c9 100644
--- a/drivers/soundwire/amd_manager.c
+++ b/drivers/soundwire/amd_manager.c
@@ -1437,15 +1437,20 @@ static int __maybe_unused amd_suspend(struct device *dev)
 	}
 
 	if (amd_manager->power_mode_mask & AMD_SDW_CLK_STOP_MODE) {
+		amd_disable_sdw_interrupts(amd_manager);
+		cancel_work_sync(&amd_manager->amd_sdw_irq_thread);
 		cancel_work_sync(&amd_manager->amd_sdw_work);
-		amd_sdw_wake_enable(amd_manager, false);
 		ret = amd_sdw_host_wake_enable_by_rev(amd_manager, false);
 		if (ret)
 			return ret;
 		ret = amd_sdw_clock_stop(amd_manager);
 		if (ret)
 			return ret;
+		amd_enable_sdw_interrupts(amd_manager);
+		amd_sdw_wake_enable(amd_manager, false);
 	} else if (amd_manager->power_mode_mask & AMD_SDW_POWER_OFF_MODE) {
+		amd_disable_sdw_interrupts(amd_manager);
+		cancel_work_sync(&amd_manager->amd_sdw_irq_thread);
 		cancel_work_sync(&amd_manager->amd_sdw_work);
 		amd_sdw_wake_enable(amd_manager, false);
 		ret = amd_sdw_host_wake_enable_by_rev(amd_manager, false);
@@ -1458,7 +1463,6 @@ static int __maybe_unused amd_suspend(struct device *dev)
 		ret = amd_sdw_clock_stop(amd_manager);
 		if (ret)
 			return ret;
-		amd_disable_sdw_interrupts(amd_manager);
 		ret = amd_disable_sdw_manager(amd_manager);
 		if (ret)
 			return ret;
@@ -1498,18 +1502,24 @@ static int __maybe_unused amd_suspend_runtime(struct device *dev)
 		return 0;
 	}
 	if (amd_manager->power_mode_mask & AMD_SDW_CLK_STOP_MODE) {
-		amd_sdw_wake_enable(amd_manager, true);
+		amd_disable_sdw_interrupts(amd_manager);
+		cancel_work_sync(&amd_manager->amd_sdw_irq_thread);
+		cancel_work_sync(&amd_manager->amd_sdw_work);
 		ret = amd_sdw_host_wake_enable_by_rev(amd_manager, true);
 		if (ret)
 			return ret;
 		ret = amd_sdw_clock_stop(amd_manager);
 		if (ret)
 			return ret;
+		amd_enable_sdw_interrupts(amd_manager);
+		amd_sdw_wake_enable(amd_manager, true);
 	} else if (amd_manager->power_mode_mask & AMD_SDW_POWER_OFF_MODE) {
+		amd_disable_sdw_interrupts(amd_manager);
+		cancel_work_sync(&amd_manager->amd_sdw_irq_thread);
+		cancel_work_sync(&amd_manager->amd_sdw_work);
 		ret = amd_sdw_clock_stop(amd_manager);
 		if (ret)
 			return ret;
-		amd_disable_sdw_interrupts(amd_manager);
 		ret = amd_disable_sdw_manager(amd_manager);
 		if (ret)
 			return ret;
-- 
2.53.0