linux-kernel - [char-misc-next 1/5] mei: me: trigger link reset if hw ready is unexpected

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250918130435.3327400-2-alexander.usyskin@intel.com>
Date: Thu, 18 Sep 2025 16:04:31 +0300
From: Alexander Usyskin <alexander.usyskin@...el.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Reuven Abliyev <reuven.abliyev@...el.com>,
	Alexander Usyskin <alexander.usyskin@...el.com>,
	linux-kernel@...r.kernel.org
Subject: [char-misc-next 1/5] 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@...el.com>
---
 drivers/misc/mei/hw-me.c   | 17 ++++++++++++++---
 drivers/misc/mei/init.c    |  2 +-
 drivers/misc/mei/mei_dev.h |  3 ++-
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 346633ebc6e6..3172dc095b53 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 4d1d5423b612..b9fb54328a7b 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 4ab2b9100fd4..9f2044ae6cc4 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,
-- 
2.43.0