Revert "net: stmmac: correct MAC propagation delay"

This reverts commit 20bf98c94146eb6fe62177817cb32f53e72dd2e8.

Richard raised concerns about correctness of the code on previous
generations of the HW.

Fixes: 20bf98c94146 ("net: stmmac: correct MAC propagation delay")
Link: https://lore.kernel.org/all/ZMGIuKVP7BEotbrn@hoboy.vegasvil.org/
Link: https://lore.kernel.org/r/20230726224054.3241127-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 40147ef..652af8f 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -532,7 +532,6 @@ struct stmmac_hwtimestamp {
        void (*get_systime) (void __iomem *ioaddr, u64 *systime);
        void (*get_ptptime)(void __iomem *ioaddr, u64 *ptp_time);
        void (*timestamp_interrupt)(struct stmmac_priv *priv);
-       void (*correct_latency)(struct stmmac_priv *priv);
 };
 
 #define stmmac_config_hw_tstamping(__priv, __args...) \
@@ -551,8 +550,6 @@ struct stmmac_hwtimestamp {
        stmmac_do_void_callback(__priv, ptp, get_ptptime, __args)
 #define stmmac_timestamp_interrupt(__priv, __args...) \
        stmmac_do_void_callback(__priv, ptp, timestamp_interrupt, __args)
-#define stmmac_correct_latency(__priv, __args...) \
-       stmmac_do_void_callback(__priv, ptp, correct_latency, __args)
 
 struct stmmac_tx_queue;
 struct stmmac_rx_queue;

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index 7e0fa02..fa2c3ba 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -60,48 +60,6 @@ static void config_sub_second_increment(void __iomem *ioaddr,
                *ssinc = data;
 }
 
-static void correct_latency(struct stmmac_priv *priv)
-{
-       void __iomem *ioaddr = priv->ptpaddr;
-       u32 reg_tsic, reg_tsicsns;
-       u32 reg_tsec, reg_tsecsns;
-       u64 scaled_ns;
-       u32 val;
-
-       /* MAC-internal ingress latency */
-       scaled_ns = readl(ioaddr + PTP_TS_INGR_LAT);
-
-       /* See section 11.7.2.5.3.1 "Ingress Correction" on page 4001 of
-        * i.MX8MP Applications Processor Reference Manual Rev. 1, 06/2021
-        */
-       val = readl(ioaddr + PTP_TCR);
-       if (val & PTP_TCR_TSCTRLSSR)
-               /* nanoseconds field is in decimal format with granularity of 1ns/bit */
-               scaled_ns = ((u64)NSEC_PER_SEC << 16) - scaled_ns;
-       else
-               /* nanoseconds field is in binary format with granularity of ~0.466ns/bit */
-               scaled_ns = ((1ULL << 31) << 16) -
-                       DIV_U64_ROUND_CLOSEST(scaled_ns * PSEC_PER_NSEC, 466U);
-
-       reg_tsic = scaled_ns >> 16;
-       reg_tsicsns = scaled_ns & 0xff00;
-
-       /* set bit 31 for 2's compliment */
-       reg_tsic |= BIT(31);
-
-       writel(reg_tsic, ioaddr + PTP_TS_INGR_CORR_NS);
-       writel(reg_tsicsns, ioaddr + PTP_TS_INGR_CORR_SNS);
-
-       /* MAC-internal egress latency */
-       scaled_ns = readl(ioaddr + PTP_TS_EGR_LAT);
-
-       reg_tsec = scaled_ns >> 16;
-       reg_tsecsns = scaled_ns & 0xff00;
-
-       writel(reg_tsec, ioaddr + PTP_TS_EGR_CORR_NS);
-       writel(reg_tsecsns, ioaddr + PTP_TS_EGR_CORR_SNS);
-}
-
 static int init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
 {
        u32 value;
@@ -263,5 +221,4 @@ const struct stmmac_hwtimestamp stmmac_ptp = {
        .get_systime = get_systime,
        .get_ptptime = get_ptptime,
        .timestamp_interrupt = timestamp_interrupt,
-       .correct_latency = correct_latency,
 };

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 19e46e8..e1f1c03 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -909,8 +909,6 @@ static int stmmac_init_ptp(struct stmmac_priv *priv)
        priv->hwts_tx_en = 0;
        priv->hwts_rx_en = 0;
 
-       stmmac_correct_latency(priv, priv);
-
        return 0;
 }
 
@@ -1096,8 +1094,6 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 
        if (priv->dma_cap.fpesel)
                stmmac_fpe_link_state_handle(priv, true);
-
-       stmmac_correct_latency(priv, priv);
 }
 
 static const struct phylink_mac_ops stmmac_phylink_mac_ops = {

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h
index d1fe4b4..bf61929 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h
@@ -26,12 +26,6 @@
 #define        PTP_ACR         0x40    /* Auxiliary Control Reg */
 #define        PTP_ATNR        0x48    /* Auxiliary Timestamp - Nanoseconds Reg */
 #define        PTP_ATSR        0x4c    /* Auxiliary Timestamp - Seconds Reg */
-#define        PTP_TS_INGR_CORR_NS     0x58    /* Ingress timestamp correction nanoseconds */
-#define        PTP_TS_EGR_CORR_NS      0x5C    /* Egress timestamp correction nanoseconds*/
-#define        PTP_TS_INGR_CORR_SNS    0x60    /* Ingress timestamp correction subnanoseconds */
-#define        PTP_TS_EGR_CORR_SNS     0x64    /* Egress timestamp correction subnanoseconds */
-#define        PTP_TS_INGR_LAT 0x68    /* MAC internal Ingress Latency */
-#define        PTP_TS_EGR_LAT  0x6c    /* MAC internal Egress Latency */
 
 #define        PTP_STNSUR_ADDSUB_SHIFT 31
 #define        PTP_DIGITAL_ROLLOVER_MODE       0x3B9ACA00      /* 10e9-1 ns */