iwlwifi: configure the LTR
The LTR is the handshake between the device and the root
complex about the latency allowed when the bus exits power
save. This configuration was missing and this led to high
latency in the link power up. The end user could experience
high latency in the network because of this.
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 1393bac..c706dba 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -174,6 +174,7 @@
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
u16 lctl;
+ u16 cap;
/*
* HW bug W/A for instability in PCIe bus L0S->L1 transition.
@@ -184,16 +185,17 @@
* power savings, even without L1.
*/
pcie_capability_read_word(trans_pcie->pci_dev, PCI_EXP_LNKCTL, &lctl);
- if (lctl & PCI_EXP_LNKCTL_ASPM_L1) {
- /* L1-ASPM enabled; disable(!) L0S */
+ if (lctl & PCI_EXP_LNKCTL_ASPM_L1)
iwl_set_bit(trans, CSR_GIO_REG, CSR_GIO_REG_VAL_L0S_ENABLED);
- dev_info(trans->dev, "L1 Enabled; Disabling L0S\n");
- } else {
- /* L1-ASPM disabled; enable(!) L0S */
+ else
iwl_clear_bit(trans, CSR_GIO_REG, CSR_GIO_REG_VAL_L0S_ENABLED);
- dev_info(trans->dev, "L1 Disabled; Enabling L0S\n");
- }
trans->pm_support = !(lctl & PCI_EXP_LNKCTL_ASPM_L0S);
+
+ pcie_capability_read_word(trans_pcie->pci_dev, PCI_EXP_DEVCTL2, &cap);
+ trans->ltr_enabled = cap & PCI_EXP_DEVCTL2_LTR_EN;
+ dev_info(trans->dev, "L1 %sabled - LTR %sabled\n",
+ (lctl & PCI_EXP_LNKCTL_ASPM_L1) ? "En" : "Dis",
+ trans->ltr_enabled ? "En" : "Dis");
}
/*