mei: amthif: don't drop read packets on timeout

Since the driver now uses a list for storing read packets instead of
single variable a pending read is no longer blocking other connections.
A pending read will be discarded up the file closure.
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>

drivers/misc/mei/amthif.c

@@ -50,7 +50,6 @@ void mei_amthif_reset_params(struct mei_device *dev)
 	dev->iamthif_current_cb = NULL;
 	dev->iamthif_canceled = false;
 	dev->iamthif_state = MEI_IAMTHIF_IDLE;
-	dev->iamthif_timer = 0;
 	dev->iamthif_stall_timer = 0;
 	dev->iamthif_open_count = 0;
 }
@@ -124,18 +123,10 @@ struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
 int mei_amthif_read(struct mei_device *dev, struct file *file,
 	       char __user *ubuf, size_t length, loff_t *offset)
 {
-	struct mei_cl *cl = file->private_data;
 	struct mei_cl_cb *cb;
-	unsigned long timeout;
 	int rets;
 	int wait_ret;
 
-	/* Only possible if we are in timeout */
-	if (!cl) {
-		dev_err(dev->dev, "bad file ext.\n");
-		return -ETIME;
-	}
-
 	dev_dbg(dev->dev, "checking amthif data\n");
 	cb = mei_amthif_find_read_list_entry(dev, file);
 
@@ -168,20 +159,6 @@ int mei_amthif_read(struct mei_device *dev, struct file *file,
 	}
 
 	dev_dbg(dev->dev, "Got amthif data\n");
-	dev->iamthif_timer = 0;
-
-	timeout = cb->read_time +
-		mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
-	dev_dbg(dev->dev, "amthif timeout = %lud\n",
-			timeout);
-
-	if  (time_after(jiffies, timeout)) {
-		dev_dbg(dev->dev, "amthif Time out\n");
-		/* 15 sec for the message has expired */
-		list_del_init(&cb->list);
-		rets = -ETIME;
-		goto free;
-	}
 	/* if the whole message will fit remove it from the list */
 	if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
 		list_del_init(&cb->list);
@@ -303,7 +280,6 @@ int mei_amthif_run_next_cmd(struct mei_device *dev)
 
 	dev->iamthif_canceled = false;
 	dev->iamthif_state = MEI_IAMTHIF_IDLE;
-	dev->iamthif_timer = 0;
 	dev->iamthif_file_object = NULL;
 
 	dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
@@ -462,9 +438,6 @@ void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
 		dev->iamthif_stall_timer = 0;
 		list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
 		dev_dbg(dev->dev, "amthif read completed\n");
-		dev->iamthif_timer = jiffies;
-		dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
-			dev->iamthif_timer);
 	} else {
 		mei_amthif_run_next_cmd(dev);
 	}

drivers/misc/mei/hw.h

@@ -29,7 +29,6 @@
 #define MEI_CLIENTS_INIT_TIMEOUT   15  /* HPS: Clients Enumeration Timeout */
 
 #define MEI_IAMTHIF_STALL_TIMER    12  /* HPS */
-#define MEI_IAMTHIF_READ_TIMER     10  /* HPS */
 
 #define MEI_PGI_TIMEOUT             1  /* PG Isolation time response 1 sec */
 #define MEI_D0I3_TIMEOUT            5  /* D0i3 set/unset max response time */

drivers/misc/mei/interrupt.c

@@ -156,7 +156,6 @@ int mei_cl_irq_read_msg(struct mei_cl *cl,
 	cb->buf_idx += mei_hdr->length;
 
 	if (mei_hdr->msg_complete) {
-		cb->read_time = jiffies;
 		cl_dbg(dev, cl, "completed read length = %lu\n", cb->buf_idx);
 		list_move_tail(&cb->list, &complete_list->list);
 	} else {
@@ -458,7 +457,6 @@ static void mei_connect_timeout(struct mei_cl *cl)
  */
 void mei_timer(struct work_struct *work)
 {
-	unsigned long timeout;
 	struct mei_cl *cl;
 
 	struct mei_device *dev = container_of(work,
@@ -504,7 +502,6 @@ void mei_timer(struct work_struct *work)
 			mei_reset(dev);
 			dev->iamthif_canceled = false;
 			dev->iamthif_state = MEI_IAMTHIF_IDLE;
-			dev->iamthif_timer = 0;
 
 			mei_io_cb_free(dev->iamthif_current_cb);
 			dev->iamthif_current_cb = NULL;
@@ -514,35 +511,6 @@ void mei_timer(struct work_struct *work)
 		}
 	}
 
-	if (dev->iamthif_timer) {
-
-		timeout = dev->iamthif_timer +
-			mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
-
-		dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
-				dev->iamthif_timer);
-		dev_dbg(dev->dev, "timeout = %ld\n", timeout);
-		dev_dbg(dev->dev, "jiffies = %ld\n", jiffies);
-		if (time_after(jiffies, timeout)) {
-			/*
-			 * User didn't read the AMTHI data on time (15sec)
-			 * freeing AMTHI for other requests
-			 */
-
-			dev_dbg(dev->dev, "freeing AMTHI for other requests\n");
-
-			mei_io_list_flush(&dev->amthif_rd_complete_list,
-				&dev->iamthif_cl);
-			mei_io_cb_free(dev->iamthif_current_cb);
-			dev->iamthif_current_cb = NULL;
-
-			dev->iamthif_file_object->private_data = NULL;
-			dev->iamthif_file_object = NULL;
-			dev->iamthif_timer = 0;
-			mei_amthif_run_next_cmd(dev);
-
-		}
-	}
 out:
 	if (dev->dev_state != MEI_DEV_DISABLED)
 		schedule_delayed_work(&dev->timer_work, 2 * HZ);

drivers/misc/mei/main.c

@@ -274,7 +274,6 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 	struct mei_cl *cl = file->private_data;
 	struct mei_cl_cb *write_cb = NULL;
 	struct mei_device *dev;
-	unsigned long timeout = 0;
 	int rets;
 
 	if (WARN_ON(!cl || !cl->dev))
@@ -310,21 +309,6 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 		goto out;
 	}
 
-	if (cl == &dev->iamthif_cl) {
-		write_cb = mei_amthif_find_read_list_entry(dev, file);
-
-		if (write_cb) {
-			timeout = write_cb->read_time +
-				mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
-
-			if (time_after(jiffies, timeout)) {
-				*offset = 0;
-				mei_io_cb_free(write_cb);
-				write_cb = NULL;
-			}
-		}
-	}
-
 	*offset = 0;
 	write_cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
 	if (!write_cb) {

drivers/misc/mei/mei_dev.h

@@ -179,7 +179,6 @@ struct mei_cl;
  * @fop_type: file operation type
  * @buf: buffer for data associated with the callback
  * @buf_idx: last read index
- * @read_time: last read operation time stamp (iamthif)
  * @file_object: pointer to file structure
  * @status: io status of the cb
  * @internal: communication between driver and FW flag
@@ -191,7 +190,6 @@ struct mei_cl_cb {
 	enum mei_cb_file_ops fop_type;
 	struct mei_msg_data buf;
 	size_t buf_idx;
-	unsigned long read_time;
 	struct file *file_object;
 	int status;
 	u32 internal:1;
@@ -413,7 +411,6 @@ const char *mei_pg_state_str(enum mei_pg_state state);
  * @iamthif_cl  : amthif host client
  * @iamthif_current_cb : amthif current operation callback
  * @iamthif_open_count : number of opened amthif connections
- * @iamthif_timer : time stamp of current amthif command completion
  * @iamthif_stall_timer : timer to detect amthif hang
  * @iamthif_state : amthif processor state
  * @iamthif_canceled : current amthif command is canceled
@@ -504,7 +501,6 @@ struct mei_device {
 	struct mei_cl iamthif_cl;
 	struct mei_cl_cb *iamthif_current_cb;
 	long iamthif_open_count;
-	unsigned long iamthif_timer;
 	u32 iamthif_stall_timer;
 	enum iamthif_states iamthif_state;
 	bool iamthif_canceled;