From: Alexander Usyskin <alexander.usyskin@intel.com>
Date: Sat, 6 Feb 2021 14:43:21 +0000 (+0200)
Subject: mei: allow clients on bus to communicate in remove callback
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=36edb1407c3c042240b5dbc2530d6e7119535baa;p=linux.git

mei: allow clients on bus to communicate in remove callback

Introduce new intermediate state to allow the clients on the bus
to communicate with the firmware from the remove handler.
This is to enable to perform a clean shutdown.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20210206144325.25682-2-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 2907db260fba5..34fb5e541fe5f 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -44,7 +44,8 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length, u8 vtag,
 	bus = cl->dev;
 
 	mutex_lock(&bus->device_lock);
-	if (bus->dev_state != MEI_DEV_ENABLED) {
+	if (bus->dev_state != MEI_DEV_ENABLED &&
+	    bus->dev_state != MEI_DEV_POWERING_DOWN) {
 		rets = -ENODEV;
 		goto out;
 	}
@@ -128,7 +129,8 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length, u8 *vtag,
 	bus = cl->dev;
 
 	mutex_lock(&bus->device_lock);
-	if (bus->dev_state != MEI_DEV_ENABLED) {
+	if (bus->dev_state != MEI_DEV_ENABLED &&
+	    bus->dev_state != MEI_DEV_POWERING_DOWN) {
 		rets = -ENODEV;
 		goto out;
 	}
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index beb6cdff20fb3..d3f060dce4a60 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -990,7 +990,8 @@ int mei_cl_disconnect(struct mei_cl *cl)
 		return 0;
 	}
 
-	if (dev->dev_state == MEI_DEV_POWER_DOWN) {
+	if (dev->dev_state == MEI_DEV_POWERING_DOWN ||
+	    dev->dev_state == MEI_DEV_POWER_DOWN) {
 		cl_dbg(dev, cl, "Device is powering down, don't bother with disconnection\n");
 		mei_cl_set_disconnected(cl);
 		return 0;
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index bcee77768b917..5c8cb679b9976 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -303,9 +303,12 @@ void mei_stop(struct mei_device *dev)
 	dev_dbg(dev->dev, "stopping the device.\n");
 
 	mutex_lock(&dev->device_lock);
-	mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
+	mei_set_devstate(dev, MEI_DEV_POWERING_DOWN);
 	mutex_unlock(&dev->device_lock);
 	mei_cl_bus_remove_devices(dev);
+	mutex_lock(&dev->device_lock);
+	mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
+	mutex_unlock(&dev->device_lock);
 
 	mei_cancel_work(dev);
 
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 8c395bfdf6f37..585a6f615bf83 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -57,6 +57,7 @@ enum mei_dev_state {
 	MEI_DEV_ENABLED,
 	MEI_DEV_RESETTING,
 	MEI_DEV_DISABLED,
+	MEI_DEV_POWERING_DOWN,
 	MEI_DEV_POWER_DOWN,
 	MEI_DEV_POWER_UP
 };