net: fec: add pm_qos support on imx6q platform

There is a very low probability that tx timeout will occur during
suspend and resume stress test on imx6q platform. So we add pm_qos
support to prevent system from entering low level idles which may
affect the transmission of tx.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://lore.kernel.org/r/20220830070148.2021947-1-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 0cebe4b..20369f1 100644 (file)
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -16,6 +16,7 @@
 
 #include <linux/clocksource.h>
 #include <linux/net_tstamp.h>
+#include <linux/pm_qos.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/timecounter.h>
 
@@ -498,6 +499,9 @@ struct bufdesc_ex {
 /* i.MX8MQ SoC integration mix wakeup interrupt signal into "int2" interrupt line. */
 #define FEC_QUIRK_WAKEUP_FROM_INT2     (1 << 22)
 
+/* i.MX6Q adds pm_qos support */
+#define FEC_QUIRK_HAS_PMQOS                    BIT(23)
+
 struct bufdesc_prop {
        int qid;
        /* Address of Rx and Tx buffers */
@@ -608,6 +612,7 @@ struct fec_enet_private {
        struct delayed_work time_keep;
        struct regulator *reg_phy;
        struct fec_stop_mode_gpr stop_gpr;
+       struct pm_qos_request pm_qos_req;
 
        unsigned int tx_align;
        unsigned int rx_align;

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index b0d60f8..111aaef 100644 (file)
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -111,7 +111,8 @@ static const struct fec_devinfo fec_imx6q_info = {
        .quirks = FEC_QUIRK_ENET_MAC | FEC_QUIRK_HAS_GBIT |
                  FEC_QUIRK_HAS_BUFDESC_EX | FEC_QUIRK_HAS_CSUM |
                  FEC_QUIRK_HAS_VLAN | FEC_QUIRK_ERR006358 |
-                 FEC_QUIRK_HAS_RACC | FEC_QUIRK_CLEAR_SETUP_MII,
+                 FEC_QUIRK_HAS_RACC | FEC_QUIRK_CLEAR_SETUP_MII |
+                 FEC_QUIRK_HAS_PMQOS,
 };
 
 static const struct fec_devinfo fec_mvf600_info = {
@@ -3244,6 +3245,9 @@ fec_enet_open(struct net_device *ndev)
        if (fep->quirks & FEC_QUIRK_ERR006687)
                imx6q_cpuidle_fec_irqs_used();
 
+       if (fep->quirks & FEC_QUIRK_HAS_PMQOS)
+               cpu_latency_qos_add_request(&fep->pm_qos_req, 0);
+
        napi_enable(&fep->napi);
        phy_start(ndev->phydev);
        netif_tx_start_all_queues(ndev);
@@ -3285,6 +3289,9 @@ fec_enet_close(struct net_device *ndev)
        fec_enet_update_ethtool_stats(ndev);
 
        fec_enet_clk_enable(ndev, false);
+       if (fep->quirks & FEC_QUIRK_HAS_PMQOS)
+               cpu_latency_qos_remove_request(&fep->pm_qos_req);
+
        pinctrl_pm_select_sleep_state(&fep->pdev->dev);
        pm_runtime_mark_last_busy(&fep->pdev->dev);
        pm_runtime_put_autosuspend(&fep->pdev->dev);