iwlwifi: configure the LTR

commit 9180ac50716a097a407c6d7e7e4589754a922260 upstream.

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.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index 656371a668daa5e2325e45fe0b576fc3e13bd307..86fb12162af206e86479c7d54d854c6d7641312f 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -548,6 +548,7 @@ enum iwl_trans_state {
  *     Set during transport allocation.
  * @hw_id_str: a string with info about HW ID. Set during transport allocation.
  * @pm_support: set to true in start_hw if link pm is supported
+ * @ltr_enabled: set to true if the LTR is enabled
  * @dev_cmd_pool: pool for Tx cmd allocation - for internal use only.
  *     The user should use iwl_trans_{alloc,free}_tx_cmd.
  * @dev_cmd_headroom: room needed for the transport's private use before the
@@ -574,6 +575,7 @@ struct iwl_trans {
        u8 rx_mpdu_cmd, rx_mpdu_cmd_hdr_size;
 
        bool pm_support;
+       bool ltr_enabled;
 
        /* The following fields are internal only */
        struct kmem_cache *dev_cmd_pool;

diff --git a/drivers/net/wireless/iwlwifi/mvm/fw-api-power.h b/drivers/net/wireless/iwlwifi/mvm/fw-api-power.h
index c3a8c86b550d45aaca72a274252960d8397d0ef6..4d8932c1cd6de0b826bbb1d131e796da9448dcf5 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/fw-api-power.h
+++ b/drivers/net/wireless/iwlwifi/mvm/fw-api-power.h
@@ -66,13 +66,46 @@
 
 /* Power Management Commands, Responses, Notifications */
 
+/**
+ * enum iwl_ltr_config_flags - masks for LTR config command flags
+ * @LTR_CFG_FLAG_FEATURE_ENABLE: Feature operational status
+ * @LTR_CFG_FLAG_HW_DIS_ON_SHADOW_REG_ACCESS: allow LTR change on shadow
+ *     memory access
+ * @LTR_CFG_FLAG_HW_EN_SHRT_WR_THROUGH: allow LTR msg send on ANY LTR
+ *     reg change
+ * @LTR_CFG_FLAG_HW_DIS_ON_D0_2_D3: allow LTR msg send on transition from
+ *     D0 to D3
+ * @LTR_CFG_FLAG_SW_SET_SHORT: fixed static short LTR register
+ * @LTR_CFG_FLAG_SW_SET_LONG: fixed static short LONG register
+ * @LTR_CFG_FLAG_DENIE_C10_ON_PD: allow going into C10 on PD
+ */
+enum iwl_ltr_config_flags {
+       LTR_CFG_FLAG_FEATURE_ENABLE = BIT(0),
+       LTR_CFG_FLAG_HW_DIS_ON_SHADOW_REG_ACCESS = BIT(1),
+       LTR_CFG_FLAG_HW_EN_SHRT_WR_THROUGH = BIT(2),
+       LTR_CFG_FLAG_HW_DIS_ON_D0_2_D3 = BIT(3),
+       LTR_CFG_FLAG_SW_SET_SHORT = BIT(4),
+       LTR_CFG_FLAG_SW_SET_LONG = BIT(5),
+       LTR_CFG_FLAG_DENIE_C10_ON_PD = BIT(6),
+};
+
+/**
+ * struct iwl_ltr_config_cmd - configures the LTR
+ * @flags: See %enum iwl_ltr_config_flags
+ */
+struct iwl_ltr_config_cmd {
+       __le32 flags;
+       __le32 static_long;
+       __le32 static_short;
+} __packed;
+
 /* Radio LP RX Energy Threshold measured in dBm */
 #define POWER_LPRX_RSSI_THRESHOLD      75
 #define POWER_LPRX_RSSI_THRESHOLD_MAX  94
 #define POWER_LPRX_RSSI_THRESHOLD_MIN  30
 
 /**
- * enum iwl_scan_flags - masks for power table command flags
+ * enum iwl_power_flags - masks for power table command flags
  * @POWER_FLAGS_POWER_SAVE_ENA_MSK: '1' Allow to save power by turning off
  *             receiver and transmitter. '0' - does not allow.
  * @POWER_FLAGS_POWER_MANAGEMENT_ENA_MSK: '0' Driver disables power management,

diff --git a/drivers/net/wireless/iwlwifi/mvm/fw-api.h b/drivers/net/wireless/iwlwifi/mvm/fw-api.h
index 9a922f3bd16bc00b7a5ce0e6484178db9372a24d..7b73ed4903c42b132d643df08589b36efd52de10 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/fw-api.h
+++ b/drivers/net/wireless/iwlwifi/mvm/fw-api.h
@@ -148,6 +148,7 @@ enum {
        /* Power - legacy power table command */
        POWER_TABLE_CMD = 0x77,
        PSM_UAPSD_AP_MISBEHAVING_NOTIFICATION = 0x78,
+       LTR_CONFIG = 0xee,
 
        /* Thermal Throttling*/
        REPLY_THERMAL_MNG_BACKOFF = 0x7e,

diff --git a/drivers/net/wireless/iwlwifi/mvm/fw.c b/drivers/net/wireless/iwlwifi/mvm/fw.c
index 883e702152d5289163f48f7464cf630f6795ec2f..bf720a875e6bfa7a13d895954a052168e0b0a774 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/iwlwifi/mvm/fw.c
@@ -475,6 +475,15 @@ int iwl_mvm_up(struct iwl_mvm *mvm)
        /* Initialize tx backoffs to the minimal possible */
        iwl_mvm_tt_tx_backoff(mvm, 0);
 
+       if (mvm->trans->ltr_enabled) {
+               struct iwl_ltr_config_cmd cmd = {
+                       .flags = cpu_to_le32(LTR_CFG_FLAG_FEATURE_ENABLE),
+               };
+
+               WARN_ON(iwl_mvm_send_cmd_pdu(mvm, LTR_CONFIG, 0,
+                                            sizeof(cmd), &cmd));
+       }
+
        ret = iwl_mvm_power_update_device(mvm);
        if (ret)
                goto error;

diff --git a/drivers/net/wireless/iwlwifi/mvm/ops.c b/drivers/net/wireless/iwlwifi/mvm/ops.c
index 610dbcb0dc279d97dda32ded4df2b387a4577333..d31a1178ae3512574dc52ccf5274ffdf46caabf9 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/iwlwifi/mvm/ops.c
@@ -332,6 +332,7 @@ static const char *const iwl_mvm_cmd_strings[REPLY_MAX] = {
        CMD(REPLY_BEACON_FILTERING_CMD),
        CMD(REPLY_THERMAL_MNG_BACKOFF),
        CMD(MAC_PM_POWER_TABLE),
+       CMD(LTR_CONFIG),
        CMD(BT_COEX_CI),
        CMD(BT_COEX_UPDATE_SW_BOOST),
        CMD(BT_COEX_UPDATE_CORUN_LUT),

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 06e04aaf61eea9609d619be4e0afdf407dd307d4..d7231a82fe425691aa31e0e9207729e87a620074 100644 (file)
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -172,6 +172,7 @@ static void iwl_pcie_apm_config(struct iwl_trans *trans)
 {
        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.
@@ -182,16 +183,17 @@ static void iwl_pcie_apm_config(struct iwl_trans *trans)
         *    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");
 }
 
 /*