iwlwifi: disable the buggy chain extension feature in HW
This feature has been reported to be buggy and enabled by
default. We therefore need to disable it manually.
Cc: stable@vger.kernel.org
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
index ec6fb39..79c6b91 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
@@ -1058,6 +1058,11 @@
iwl_write_prph(trans, SCD_DRAM_BASE_ADDR,
trans_pcie->scd_bc_tbls.dma >> 10);
+ /* 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);
+
/* Enable DMA channel */
for (chan = 0; chan < FH_TCSR_CHNL_NUM ; chan++)
iwl_write_direct32(trans, FH_TCSR_CHNL_TX_CONFIG_REG(chan),