iwlwifi: pcie: workaround HW shadow registers bug
Integrated 9000 devices have a bug with shadow registers
value retention.
If driver writes RBD registers while MAC is asleep the
values are stored in shadow registers to be copied whenever
MAC wakes up.
However, in 9000 devices a MAC wakeup is not triggered
and when the bus powers down due to inactivity the shadow
values and dirty bits are lost.
Turn on the chicken-bits that cause MAC wakeup for RX-related
values as well when the device is in D0.
When the device is in low power mode turn the RX wakeup chicken
bits off since driver is idle and this W/A is not needed.
Remove previous W/A which was ineffective.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
index de6974f..482836e 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
@@ -673,4 +673,6 @@
int iwl_pci_fw_exit_d0i3(struct iwl_trans *trans);
int iwl_pci_fw_enter_d0i3(struct iwl_trans *trans);
+void iwl_pcie_enable_rx_wake(struct iwl_trans *trans, bool enable);
+
#endif /* __iwl_trans_int_pcie_h__ */
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
index 0a4a3c5..f1e309d 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
@@ -211,12 +211,8 @@
if (trans->cfg->mq_rx_supported)
iwl_write32(trans, RFH_Q_FRBDCB_WIDX_TRG(rxq->id),
rxq->write_actual);
- /*
- * write to FH_RSCSR_CHNL0_WPTR register even in MQ as a W/A to
- * hardware shadow registers bug - writing to RFH_Q_FRBDCB_WIDX will
- * not wake the NIC.
- */
- iwl_write32(trans, FH_RSCSR_CHNL0_WPTR, rxq->write_actual);
+ else
+ iwl_write32(trans, FH_RSCSR_CHNL0_WPTR, rxq->write_actual);
}
static void iwl_pcie_rxq_check_wrptr(struct iwl_trans *trans)
@@ -764,6 +760,23 @@
iwl_set_bit(trans, CSR_INT_COALESCING, IWL_HOST_INT_OPER_MODE);
}
+void iwl_pcie_enable_rx_wake(struct iwl_trans *trans, bool enable)
+{
+ /*
+ * Turn on the chicken-bits that cause MAC wakeup for RX-related
+ * values.
+ * This costs some power, but needed for W/A 9000 integrated A-step
+ * bug where shadow registers are not in the retention list and their
+ * value is lost when NIC powers down
+ */
+ if (trans->cfg->integrated) {
+ iwl_set_bit(trans, CSR_MAC_SHADOW_REG_CTRL,
+ CSR_MAC_SHADOW_REG_CTRL_RX_WAKE);
+ iwl_set_bit(trans, CSR_MAC_SHADOW_REG_CTL2,
+ CSR_MAC_SHADOW_REG_CTL2_RX_WAKE);
+ }
+}
+
static void iwl_pcie_rx_mq_hw_init(struct iwl_trans *trans)
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
@@ -849,6 +862,8 @@
/* Set interrupt coalescing timer to default (2048 usecs) */
iwl_write8(trans, CSR_INT_COALESCING, IWL_HOST_INT_TIMEOUT_DEF);
+
+ iwl_pcie_enable_rx_wake(trans, true);
}
static void iwl_pcie_rx_init_rxb_lists(struct iwl_rxq *rxq)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index f603d78..33fd217 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -1286,6 +1286,8 @@
iwl_clear_bit(trans, CSR_GP_CNTRL,
CSR_GP_CNTRL_REG_FLAG_INIT_DONE);
+ iwl_pcie_enable_rx_wake(trans, false);
+
if (reset) {
/*
* reset TX queues -- some of their registers reset during S3
@@ -1311,6 +1313,8 @@
return 0;
}
+ iwl_pcie_enable_rx_wake(trans, true);
+
/*
* Also enables interrupts - none will happen as the device doesn't
* know we're waking it up, only when the opmode actually tells it