mei: limit the number of consecutive resets

give up reseting after 3 unsuccessful tries

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 4f268a3..1ee2b94 100644 (file)
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -370,6 +370,7 @@ void mei_host_client_init(struct work_struct *work)
        }
 
        dev->dev_state = MEI_DEV_ENABLED;
+       dev->reset_count = 0;
 
        mutex_unlock(&dev->device_lock);
 }

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index 059133d..cdd31c2 100644 (file)
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -89,6 +89,13 @@ int mei_reset(struct mei_device *dev)
        interrupts_enabled = state != MEI_DEV_POWER_DOWN;
        dev->dev_state = MEI_DEV_RESETTING;
 
+       dev->reset_count++;
+       if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
+               dev_err(&dev->pdev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
+               dev->dev_state = MEI_DEV_DISABLED;
+               return -ENODEV;
+       }
+
        ret = mei_hw_reset(dev, interrupts_enabled);
        /* fall through and remove the sw state even if hw reset has failed */
 
@@ -169,6 +176,7 @@ int mei_start(struct mei_device *dev)
        dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
 
        dev->dev_state = MEI_DEV_INITIALIZING;
+       dev->reset_count = 0;
        mei_reset(dev);
 
        if (dev->dev_state == MEI_DEV_DISABLED) {
@@ -224,6 +232,7 @@ int mei_restart(struct mei_device *dev)
        mei_clear_interrupts(dev);
 
        dev->dev_state = MEI_DEV_POWER_UP;
+       dev->reset_count = 0;
 
        err = mei_reset(dev);
 
@@ -285,6 +294,7 @@ void mei_device_init(struct mei_device *dev)
        init_waitqueue_head(&dev->wait_recvd_msg);
        init_waitqueue_head(&dev->wait_stop_wd);
        dev->dev_state = MEI_DEV_INITIALIZING;
+       dev->reset_count = 0;
 
        mei_io_list_init(&dev->read_list);
        mei_io_list_init(&dev->write_list);

diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index a617c84..f7de95b 100644 (file)
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -61,6 +61,11 @@ extern const uuid_le mei_wd_guid;
 #define MEI_CLIENTS_MAX 256
 
 /*
+ * maximum number of consecutive resets
+ */
+#define MEI_MAX_CONSEC_RESET  3
+
+/*
  * Number of File descriptors/handles
  * that can be opened to the driver.
  *
@@ -327,6 +332,7 @@ struct mei_cl_device {
 /**
  * struct mei_device -  MEI private device struct
 
+ * @reset_count - limits the number of consecutive resets
  * @hbm_state - state of host bus message protocol
  * @mem_addr - mem mapped base register address
 
@@ -370,6 +376,7 @@ struct mei_device {
        /*
         * mei device  states
         */
+       unsigned long reset_count;
        enum mei_dev_state dev_state;
        enum mei_hbm_state hbm_state;
        u16 init_clients_timer;