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 2907db2..34fb5e5 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 beb6cdf..d3f060d 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 bcee777..5c8cb67 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 8c395bf..585a6f6 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
 };