rtw88: allows to enable/disable HCI link PS mechanism

Different interfaces have its own link-related power save mechanism.
Such as PCI can enter L1 state based on the traffic on the link, and
sometimes driver needs to enable/disable it to avoid some issues, like
throughput degrade when PCI trying to enter L1 state even if driver is
having heavy traffic.

For now, rtw88 only supports PCIE chips, and they just need to disable
ASPM L1 when driver is not in power save mode, such as IPS and LPS.

Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/realtek/rtw88/hci.h b/drivers/net/wireless/realtek/rtw88/hci.h
index 4afbf0d..3d91aea 100644 (file)
--- a/drivers/net/wireless/realtek/rtw88/hci.h
+++ b/drivers/net/wireless/realtek/rtw88/hci.h
@@ -14,6 +14,7 @@ struct rtw_hci_ops {
        int (*start)(struct rtw_dev *rtwdev);
        void (*stop)(struct rtw_dev *rtwdev);
        void (*deep_ps)(struct rtw_dev *rtwdev, bool enter);
+       void (*link_ps)(struct rtw_dev *rtwdev, bool enter);
 
        int (*write_data_rsvd_page)(struct rtw_dev *rtwdev, u8 *buf, u32 size);
        int (*write_data_h2c)(struct rtw_dev *rtwdev, u8 *buf, u32 size);
@@ -53,6 +54,11 @@ static inline void rtw_hci_deep_ps(struct rtw_dev *rtwdev, bool enter)
        rtwdev->hci.ops->deep_ps(rtwdev, enter);
 }
 
+static inline void rtw_hci_link_ps(struct rtw_dev *rtwdev, bool enter)
+{
+       rtwdev->hci.ops->link_ps(rtwdev, enter);
+}
+
 static inline int
 rtw_hci_write_data_rsvd_page(struct rtw_dev *rtwdev, u8 *buf, u32 size)
 {

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index 6e99aad..a58e827 100644 (file)
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -1150,6 +1150,43 @@ static void rtw_pci_clkreq_set(struct rtw_dev *rtwdev, bool enable)
        rtw_dbi_write8(rtwdev, RTK_PCIE_LINK_CFG, value);
 }
 
+static void rtw_pci_aspm_set(struct rtw_dev *rtwdev, bool enable)
+{
+       u8 value;
+       int ret;
+
+       ret = rtw_dbi_read8(rtwdev, RTK_PCIE_LINK_CFG, &value);
+       if (ret) {
+               rtw_err(rtwdev, "failed to read ASPM, ret=%d", ret);
+               return;
+       }
+
+       if (enable)
+               value |= BIT_L1_SW_EN;
+       else
+               value &= ~BIT_L1_SW_EN;
+
+       rtw_dbi_write8(rtwdev, RTK_PCIE_LINK_CFG, value);
+}
+
+static void rtw_pci_link_ps(struct rtw_dev *rtwdev, bool enter)
+{
+       struct rtw_pci *rtwpci = (struct rtw_pci *)rtwdev->priv;
+
+       /* Like CLKREQ, ASPM is also implemented by two HW modules, and can
+        * only be enabled when host supports it.
+        *
+        * And ASPM mechanism should be enabled when driver/firmware enters
+        * power save mode, without having heavy traffic. Because we've
+        * experienced some inter-operability issues that the link tends
+        * to enter L1 state on the fly even when driver is having high
+        * throughput. This is probably because the ASPM behavior slightly
+        * varies from different SOC.
+        */
+       if (rtwpci->link_ctrl & PCI_EXP_LNKCTL_ASPM_L1)
+               rtw_pci_aspm_set(rtwdev, enter);
+}
+
 static void rtw_pci_link_cfg(struct rtw_dev *rtwdev)
 {
        struct rtw_pci *rtwpci = (struct rtw_pci *)rtwdev->priv;
@@ -1292,6 +1329,7 @@ static struct rtw_hci_ops rtw_pci_ops = {
        .start = rtw_pci_start,
        .stop = rtw_pci_stop,
        .deep_ps = rtw_pci_deep_ps,
+       .link_ps = rtw_pci_link_ps,
 
        .read8 = rtw_pci_read8,
        .read16 = rtw_pci_read16,

diff --git a/drivers/net/wireless/realtek/rtw88/pci.h b/drivers/net/wireless/realtek/rtw88/pci.h
index 90efb73..49bf29a 100644 (file)
--- a/drivers/net/wireless/realtek/rtw88/pci.h
+++ b/drivers/net/wireless/realtek/rtw88/pci.h
@@ -38,6 +38,7 @@
 
 #define RTK_PCIE_LINK_CFG      0x0719
 #define BIT_CLKREQ_SW_EN       BIT(4)
+#define BIT_L1_SW_EN           BIT(3)
 
 #define BIT_PCI_BCNQ_FLAG      BIT(4)
 #define RTK_PCI_TXBD_DESA_BCNQ 0x308

diff --git a/drivers/net/wireless/realtek/rtw88/ps.c b/drivers/net/wireless/realtek/rtw88/ps.c
index 2226e3e..913e6f4 100644 (file)
--- a/drivers/net/wireless/realtek/rtw88/ps.c
+++ b/drivers/net/wireless/realtek/rtw88/ps.c
@@ -31,6 +31,7 @@ int rtw_enter_ips(struct rtw_dev *rtwdev)
        rtw_coex_ips_notify(rtwdev, COEX_IPS_ENTER);
 
        rtw_core_stop(rtwdev);
+       rtw_hci_link_ps(rtwdev, true);
 
        return 0;
 }
@@ -49,6 +50,8 @@ int rtw_leave_ips(struct rtw_dev *rtwdev)
 {
        int ret;
 
+       rtw_hci_link_ps(rtwdev, false);
+
        ret = rtw_ips_pwr_up(rtwdev);
        if (ret) {
                rtw_err(rtwdev, "failed to leave ips state\n");
@@ -150,6 +153,7 @@ static void rtw_leave_lps_core(struct rtw_dev *rtwdev)
        conf->rlbm = 0;
        conf->smart_ps = 0;
 
+       rtw_hci_link_ps(rtwdev, false);
        rtw_fw_set_pwr_mode(rtwdev);
        rtw_fw_leave_lps_state_check(rtwdev);
 
@@ -187,6 +191,8 @@ static void rtw_enter_lps_core(struct rtw_dev *rtwdev)
        rtw_coex_lps_notify(rtwdev, COEX_LPS_ENABLE);
 
        rtw_fw_set_pwr_mode(rtwdev);
+       rtw_hci_link_ps(rtwdev, true);
+
        set_bit(RTW_FLAG_LEISURE_PS, rtwdev->flags);
 }