Merge patch series "mei: connect to card in D3cold"

Alexander Usyskin <alexander.usyskin@intel.com> says:

When discrete graphic card enters D3cold th CSC engine is powered down.

On wakeup from the D3cold full HECI link reset is required.  The driver
should detect that firmware requests link reset and initiate the link
reset flow.

In the usual flow the connect IOCTL will trigger the wake from D3cold
and corresponding link reset.  The MEI driver invalidates all open
handles on link reset including the one that triggered the wake
rendering this connection unusable.  To break this loop make connect
detect that it is interrupted by link reset and retry connect attempt
after reset was completed.

Link: https://lore.kernel.org/r/20250918130435.3327400-1-alexander.usyskin@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 34 insertions, 9 deletions

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 93c518bb5e14..86a73684a373 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -423,6 +423,7 @@ static int mei_ioctl_connect_client(struct file *file,
 	    cl->state != MEI_FILE_DISCONNECTED)
 		return  -EBUSY;
 
+retry:
 	/* find ME client we're trying to connect to */
 	me_cl = mei_me_cl_by_uuid(dev, in_client_uuid);
 	if (!me_cl) {
@@ -454,6 +455,28 @@ static int mei_ioctl_connect_client(struct file *file,
 
 	rets = mei_cl_connect(cl, me_cl, file);
 
+	if (rets && cl->status == -EFAULT &&
+	    (dev->dev_state == MEI_DEV_RESETTING ||
+	     dev->dev_state == MEI_DEV_INIT_CLIENTS)) {
+		/* in link reset, wait for it completion */
+		mutex_unlock(&dev->device_lock);
+		rets = wait_event_interruptible_timeout(dev->wait_dev_state,
+							dev->dev_state == MEI_DEV_ENABLED,
+							dev->timeouts.link_reset_wait);
+		mutex_lock(&dev->device_lock);
+		if (rets < 0) {
+			if (signal_pending(current))
+				rets = -EINTR;
+			goto end;
+		}
+		if (dev->dev_state != MEI_DEV_ENABLED) {
+			rets = -ETIME;
+			goto end;
+		}
+		mei_me_cl_put(me_cl);
+		goto retry;
+	}
+
 end:
 	mei_me_cl_put(me_cl);
 	return rets;
@@ -646,7 +669,7 @@ static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 	struct mei_cl *cl = file->private_data;
 	struct mei_connect_client_data conn;
 	struct mei_connect_client_data_vtag conn_vtag;
-	const uuid_le *cl_uuid;
+	uuid_le cl_uuid;
 	struct mei_client *props;
 	u8 vtag;
 	u32 notify_get, notify_req;
@@ -674,18 +697,18 @@ static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 			rets = -EFAULT;
 			goto out;
 		}
-		cl_uuid = &conn.in_client_uuid;
+		cl_uuid = conn.in_client_uuid;
 		props = &conn.out_client_properties;
 		vtag = 0;
 
-		rets = mei_vt_support_check(dev, cl_uuid);
+		rets = mei_vt_support_check(dev, &cl_uuid);
 		if (rets == -ENOTTY)
 			goto out;
 		if (!rets)
-			rets = mei_ioctl_connect_vtag(file, cl_uuid, props,
+			rets = mei_ioctl_connect_vtag(file, &cl_uuid, props,
 						      vtag);
 		else
-			rets = mei_ioctl_connect_client(file, cl_uuid, props);
+			rets = mei_ioctl_connect_client(file, &cl_uuid, props);
 		if (rets)
 			goto out;
 
@@ -707,14 +730,14 @@ static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 			goto out;
 		}
 
-		cl_uuid = &conn_vtag.connect.in_client_uuid;
+		cl_uuid = conn_vtag.connect.in_client_uuid;
 		props = &conn_vtag.out_client_properties;
 		vtag = conn_vtag.connect.vtag;
 
-		rets = mei_vt_support_check(dev, cl_uuid);
+		rets = mei_vt_support_check(dev, &cl_uuid);
 		if (rets == -EOPNOTSUPP)
 			cl_dbg(dev, cl, "FW Client %pUl does not support vtags\n",
-				cl_uuid);
+				&cl_uuid);
 		if (rets)
 			goto out;
 
@@ -724,7 +747,7 @@ static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 			goto out;
 		}
 
-		rets = mei_ioctl_connect_vtag(file, cl_uuid, props, vtag);
+		rets = mei_ioctl_connect_vtag(file, &cl_uuid, props, vtag);
 		if (rets)
 			goto out;
 
@@ -1120,6 +1143,8 @@ void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state)
 
 	dev->dev_state = state;
 
+	wake_up_interruptible_all(&dev->wait_dev_state);
+
 	if (!dev->cdev)
 		return;