iwlwifi: don't disable SCD chain extension on newer devices
7000 device series have a fix for this hardware feature.
Stop disabling it, and get an improvement in Tx throughput.
This feature allows the scheduler to fetch more frames on
the fly while an A-MPDU is being built - which means that
we can get larger A-MPDU. This, of course, give an
improvement in the Tx throughput.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c
index 78a6ff2..dde6031 100644
--- a/drivers/net/wireless/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/tx.c
@@ -696,7 +696,8 @@
/* The chain extension of the SCD doesn't work well. This feature is
* enabled by default by the HW, so we need to disable it manually.
*/
- iwl_write_prph(trans, SCD_CHAINEXT_EN, 0);
+ if (trans->cfg->base_params->scd_chain_ext_wa)
+ iwl_write_prph(trans, SCD_CHAINEXT_EN, 0);
iwl_trans_ac_txq_enable(trans, trans_pcie->cmd_queue,
trans_pcie->cmd_fifo);