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 2907db260fba5ead002155992ac513e0fca3104a..34fb5e541fe5fb1a3969f08814d60a31e1a58a71 100644 (file)
--- 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 beb6cdff20fb35c5f53ec014b01fc5ed5906aa36..d3f060dce4a6013b7168df28a79231d3be7e21bf 100644 (file)
--- 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 bcee77768b91762566ff238e6a5c6308dd9994aa..5c8cb679b997629e9913112391d2e57673df4bc3 100644 (file)
--- 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 8c395bfdf6f37404f00b6d250d510f24b3301684..585a6f615bf83f79cc27426d6190df274fee98f0 100644 (file)
--- 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
 };