From: Alexander Usyskin <alexander.usys...@intel.com>
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: Alexander Usyskin <alexander.usys...@intel.com>
Signed-off-by: Tomas Winkler <tomas.wink...@intel.com>
---
drivers/misc/mei/client.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index a6c87c713193..72e32615acd9 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1422,6 +1422,25 @@ out:
}
/**
+ * 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.
*
* @cl: host client
@@ -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)) {
--
2.4.3
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