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Commit 13cf9885 authored by Alexander Usyskin's avatar Alexander Usyskin Committed by Greg Kroah-Hartman
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mei: prevent queuing new flow control credit. 



The MEI  FW can receive only one flow control for read.
Currently the driver only checks if a flow control credit was already
sent and read is pending in the rd_pending queue, but it also has to
check if flow control credit already queued in the write control queue
to prevent sending more than one flow control credits.

Signed-off-by: default avatarAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2bcfdc23

drivers/misc/mei/client.c

+20 −1
Original line number Diff line number Diff line
@@ -1421,6 +1421,25 @@ int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev) 
	return 0;

}



/**

 * mei_cl_is_read_fc_cb - check if read cb is waiting for flow control

 *                        for given host client

 *

 * @cl: host client

 *

 * Return: true, if found at least one cb.

 */

static bool mei_cl_is_read_fc_cb(struct mei_cl *cl)

{

	struct mei_device *dev = cl->dev;

	struct mei_cl_cb *cb;



	list_for_each_entry(cb, &dev->ctrl_wr_list.list, list)

		if (cb->fop_type == MEI_FOP_READ && cb->cl == cl)

			return true;

	return false;

}



/**

 * mei_cl_read_start - the start read client message function.

 *
@@ -1445,7 +1464,7 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length, struct file *fp) 
		return -ENODEV;



	/* HW currently supports only one pending read */

	if (!list_empty(&cl->rd_pending))

	if (!list_empty(&cl->rd_pending) || mei_cl_is_read_fc_cb(cl))

		return -EBUSY;



	if (!mei_me_cl_is_active(cl->me_cl)) {