mei: amthif: fix request cancel

Currently, all requests cancelled by the user are immediately removed
from the queues. Such removal can cause unexpected behavior in the case
when a request is partially written or a  reply is received after the
request is cancelled.  To resolve this a request is always fully
processed and the result is discarded in case the request was canceled.
This completes the partial fix in commit:
9d04ee1 ("mei: amthif: discard not read messages")

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

diff --git a/drivers/misc/mei/amthif.c b/drivers/misc/mei/amthif.c
index 13d8904..0cded8a 100644 (file)
--- a/drivers/misc/mei/amthif.c
+++ b/drivers/misc/mei/amthif.c
@@ -399,34 +399,44 @@ void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 {
        struct mei_device *dev = cl->dev;
 
-       if (cb->fop_type == MEI_FOP_WRITE) {
+       dev_dbg(dev->dev, "completing amthif call back.\n");
+       switch (cb->fop_type) {
+       case MEI_FOP_WRITE:
                if (!cb->status) {
                        dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
                        mei_io_cb_free(cb);
                        return;
                }
-               /*
-                * in case of error enqueue the write cb to complete read list
-                * so it can be propagated to the reader
-                */
-               list_add_tail(&cb->list, &cl->rd_completed);
-               wake_up_interruptible(&cl->rx_wait);
-               return;
-       }
+               dev->iamthif_current_cb = NULL;
+               dev->iamthif_state = MEI_IAMTHIF_IDLE;
+               dev->iamthif_fp = NULL;
+               if (!dev->iamthif_canceled) {
+                       /*
+                        * in case of error enqueue the write cb to complete
+                        * read list so it can be propagated to the reader
+                        */
+                       list_add_tail(&cb->list, &cl->rd_completed);
+                       wake_up_interruptible(&cl->rx_wait);
+               } else {
+                       mei_io_cb_free(cb);
+               }
+               break;
+       case MEI_FOP_READ:
+               if (!dev->iamthif_canceled) {
+                       list_add_tail(&cb->list, &cl->rd_completed);
+                       dev_dbg(dev->dev, "amthif read completed\n");
+                       wake_up_interruptible(&cl->rx_wait);
+               } else {
+                       mei_io_cb_free(cb);
+               }
 
-       if (!dev->iamthif_canceled) {
-               list_add_tail(&cb->list, &cl->rd_completed);
-               dev_dbg(dev->dev, "amthif read completed\n");
-       } else {
-               mei_io_cb_free(cb);
+               dev->iamthif_current_cb = NULL;
+               dev->iamthif_stall_timer = 0;
+               mei_amthif_run_next_cmd(dev);
+               break;
+       default:
+               WARN_ON(1);
        }
-
-       dev->iamthif_current_cb = NULL;
-       dev->iamthif_stall_timer = 0;
-       mei_amthif_run_next_cmd(dev);
-
-       dev_dbg(dev->dev, "completing amthif call back.\n");
-       wake_up_interruptible(&cl->rx_wait);
 }
 
 /**
@@ -439,32 +449,15 @@ void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
  *
  * mei_clear_list is called to clear resources associated with file
  * when application calls close function or Ctrl-C was pressed
- *
- * Return: true if callback removed from the list, false otherwise
  */
-static bool mei_clear_list(struct mei_device *dev,
+static void mei_clear_list(struct mei_device *dev,
                const struct file *file, struct list_head *mei_cb_list)
 {
-       struct mei_cl *cl = &dev->iamthif_cl;
        struct mei_cl_cb *cb, *next;
-       bool removed = false;
-
-       /* list all list member */
-       list_for_each_entry_safe(cb, next, mei_cb_list, list) {
-               /* check if list member associated with a file */
-               if (file == cb->fp) {
-                       /* check if cb equal to current iamthif cb */
-                       if (dev->iamthif_current_cb == cb) {
-                               dev->iamthif_current_cb = NULL;
-                               /* send flow control to iamthif client */
-                               mei_hbm_cl_flow_control_req(dev, cl);
-                       }
-                       /* free all allocated buffers */
+
+       list_for_each_entry_safe(cb, next, mei_cb_list, list)
+               if (file == cb->fp)
                        mei_io_cb_free(cb);
-                       removed = true;
-               }
-       }
-       return removed;
 }
 
 /**
@@ -475,41 +468,14 @@ static bool mei_clear_list(struct mei_device *dev,
  *
  * mei_clear_lists is called to clear resources associated with file
  * when application calls close function or Ctrl-C was pressed
- *
- * Return: true if callback removed from the list, false otherwise
  */
-static bool mei_clear_lists(struct mei_device *dev, const struct file *file)
+static void mei_clear_lists(struct mei_device *dev, const struct file *file)
 {
-       bool removed = false;
        struct mei_cl *cl = &dev->iamthif_cl;
 
-       /* remove callbacks associated with a file */
        mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
-       if (mei_clear_list(dev, file, &cl->rd_completed))
-               removed = true;
-
+       mei_clear_list(dev, file, &cl->rd_completed);
        mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
-
-       if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
-               removed = true;
-
-       if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
-               removed = true;
-
-       if (mei_clear_list(dev, file, &dev->write_list.list))
-               removed = true;
-
-       /* check if iamthif_current_cb not NULL */
-       if (dev->iamthif_current_cb && !removed) {
-               /* check file and iamthif current cb association */
-               if (dev->iamthif_current_cb->fp == file) {
-                       /* remove cb */
-                       mei_io_cb_free(dev->iamthif_current_cb);
-                       dev->iamthif_current_cb = NULL;
-                       removed = true;
-               }
-       }
-       return removed;
 }
 
 /**
@@ -533,8 +499,7 @@ int mei_amthif_release(struct mei_device *dev, struct file *file)
                dev->iamthif_canceled = true;
        }
 
-       if (mei_clear_lists(dev, file))
-               dev->iamthif_state = MEI_IAMTHIF_IDLE;
+       mei_clear_lists(dev, file);
 
        return 0;
 }

diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 3831a7b..38db1c3 100644 (file)
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -514,8 +514,6 @@ void mei_timer(struct work_struct *work)
                if (--dev->iamthif_stall_timer == 0) {
                        dev_err(dev->dev, "timer: amthif  hanged.\n");
                        mei_reset(dev);
-                       dev->iamthif_canceled = false;
-                       dev->iamthif_state = MEI_IAMTHIF_IDLE;
 
                        mei_io_cb_free(dev->iamthif_current_cb);
                        dev->iamthif_current_cb = NULL;