From: Alexander Usyskin <alexander.usyskin@intel.com>
Date: Thu, 18 Sep 2025 13:04:31 +0000 (+0300)
Subject: mei: me: trigger link reset if hw ready is unexpected
X-Git-Tag: v6.18-rc1~74^2~10^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2cedb296988c384e1555d74fb55e3b7b9fb268ae;p=thirdparty%2Fkernel%2Flinux.git

mei: me: trigger link reset if hw ready is unexpected

Driver can receive HW not ready interrupt unexpectedly.
E.g. for cards that go donwn to D3cold.
Trigger link reset in this case to synchronize driver and
firmware state.
No need to do that sync if driver is going down or interrupt is
received before driver started initial link reset sequence.
Introduce UNINITIALIZED device state to allow interrupt handler
to ignore interrupts before first init.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250918130435.3327400-2-alexander.usyskin@intel.com
---

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 346633ebc6e60..3172dc095b53e 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -1373,9 +1373,20 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
 	/*  check if we need to start the dev */
 	if (!mei_host_is_ready(dev)) {
 		if (mei_hw_is_ready(dev)) {
-			dev_dbg(&dev->dev, "we need to start the dev.\n");
-			dev->recvd_hw_ready = true;
-			wake_up(&dev->wait_hw_ready);
+			/* synchronized by dev mutex */
+			if (waitqueue_active(&dev->wait_hw_ready)) {
+				dev_dbg(&dev->dev, "we need to start the dev.\n");
+				dev->recvd_hw_ready = true;
+				wake_up(&dev->wait_hw_ready);
+			} else if (dev->dev_state != MEI_DEV_UNINITIALIZED &&
+				   dev->dev_state != MEI_DEV_POWERING_DOWN &&
+				   dev->dev_state != MEI_DEV_POWER_DOWN) {
+				dev_dbg(&dev->dev, "Force link reset.\n");
+				schedule_work(&dev->reset_work);
+			} else {
+				dev_dbg(&dev->dev, "Ignore this interrupt in state = %d\n",
+					dev->dev_state);
+			}
 		} else {
 			dev_dbg(&dev->dev, "Spurious Interrupt\n");
 		}
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index 4d1d5423b6126..b9fb54328a7b1 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -399,7 +399,7 @@ void mei_device_init(struct mei_device *dev,
 	init_waitqueue_head(&dev->wait_hw_ready);
 	init_waitqueue_head(&dev->wait_pg);
 	init_waitqueue_head(&dev->wait_hbm_start);
-	dev->dev_state = MEI_DEV_INITIALIZING;
+	dev->dev_state = MEI_DEV_UNINITIALIZED;
 	dev->reset_count = 0;
 
 	INIT_LIST_HEAD(&dev->write_list);
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 4ab2b9100fd4f..9f2044ae6cc44 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -57,7 +57,8 @@ enum file_state {
 
 /* MEI device states */
 enum mei_dev_state {
-	MEI_DEV_INITIALIZING = 0,
+	MEI_DEV_UNINITIALIZED = 0,
+	MEI_DEV_INITIALIZING,
 	MEI_DEV_INIT_CLIENTS,
 	MEI_DEV_ENABLED,
 	MEI_DEV_RESETTING,