Messages in this thread Patch in this message | | | From | Tomas Winkler <> | Subject | [char-misc-next 3/6 RESEND] mei: prevent queuing new flow control credit. | Date | Thu, 7 Jan 2016 14:46:36 +0200 |
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From: Alexander Usyskin <alexander.usyskin@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.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@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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