[PATCH 4.8 102/125] iwlwifi: mvm: call a different txq_enable function

From: Greg Kroah-Hartman
Date: Sat Oct 29 2016 - 10:03:59 EST


4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sara Sharon <sara.sharon@xxxxxxxxx>

commit ca3b9c6b6d4db9a8ba5fc8b95664e75468c59f9f upstream.

Since the SCD_QUEUE_CFG command was introduced the driver
calls iwl_trans_txq_enable_cfg() with a NULL for scd_cfg
parameter.
This makes the transport avoid writing to the SCD pointers,
since it can cause races with firmware, which is also accessing
the registers.
The transport only updates the write pointer in that case.
Fix a wrong call to iwl_trans_txq_enable() which caused a
scd_cfg parameter to be sent to transport, resulting with an
access to SCD registers.

Fixes: 58f2cc57dc6a ("iwlwifi: mvm: support dqa-mode scd queue redirection")
Signed-off-by: Sara Sharon <sara.sharon@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/intel/iwlwifi/mvm/sta.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -576,9 +576,7 @@ static int iwl_mvm_scd_queue_redirect(st
ret);

/* Make sure the SCD wrptr is correctly set before reconfiguring */
- iwl_trans_txq_enable(mvm->trans, queue, iwl_mvm_ac_to_tx_fifo[ac],
- cmd.sta_id, tid, LINK_QUAL_AGG_FRAME_LIMIT_DEF,
- ssn, wdg_timeout);
+ iwl_trans_txq_enable_cfg(mvm->trans, queue, ssn, NULL, wdg_timeout);

/* TODO: Work-around SCD bug when moving back by multiples of 0x40 */