Re: [PATCH v2] net: stmmac: fix FPE events losing

From: Serge Semin
Date: Mon Nov 27 2023 - 05:21:04 EST


Hi Jianheng

On Mon, Nov 27, 2023 at 07:08:17AM +0000, Jianheng Zhang wrote:
>
> The status bits of register MAC_FPE_CTRL_STS are clear on read. Using
> 32-bit read for MAC_FPE_CTRL_STS in dwmac5_fpe_configure() and
> dwmac5_fpe_send_mpacket() clear the status bits. Then the stmmac interrupt
> handler missing FPE event status and leads to FPE handshaking failure and
> retries.
> To avoid clear status bits of MAC_FPE_CTRL_STS in dwmac5_fpe_configure()
> and dwmac5_fpe_send_mpacket(), add fpe_csr to stmmac_fpe_cfg structure to
> cache the control bits of MAC_FPE_CTRL_STS and to avoid reading
> MAC_FPE_CTRL_STS in those methods.
>
> Fixes: 5a5586112b92 ("net: stmmac: support FPE link partner hand-shaking procedure")
> Signed-off-by: jianheng <jianheng@xxxxxxxxxxxx>

Thanks for the fix and taking all my notes and nitpicks into account.
Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx>

-Serge(y)

> ---
> drivers/net/ethernet/stmicro/stmmac/dwmac5.c | 45 +++++++++-------------
> drivers/net/ethernet/stmicro/stmmac/dwmac5.h | 4 +-
> .../net/ethernet/stmicro/stmmac/dwxgmac2_core.c | 3 +-
> drivers/net/ethernet/stmicro/stmmac/hwif.h | 4 +-
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 +++-
> drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 1 +
> include/linux/stmmac.h | 1 +
> 7 files changed, 36 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
> index e95d35f..8fd1675 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
> @@ -710,28 +710,22 @@ void dwmac5_est_irq_status(void __iomem *ioaddr, struct net_device *dev,
> }
> }
>
> -void dwmac5_fpe_configure(void __iomem *ioaddr, u32 num_txq, u32 num_rxq,
> +void dwmac5_fpe_configure(void __iomem *ioaddr, struct stmmac_fpe_cfg *cfg,
> + u32 num_txq, u32 num_rxq,
> bool enable)
> {
> u32 value;
>
> - if (!enable) {
> - value = readl(ioaddr + MAC_FPE_CTRL_STS);
> -
> - value &= ~EFPE;
> -
> - writel(value, ioaddr + MAC_FPE_CTRL_STS);
> - return;
> + if (enable) {
> + cfg->fpe_csr = EFPE;
> + value = readl(ioaddr + GMAC_RXQ_CTRL1);
> + value &= ~GMAC_RXQCTRL_FPRQ;
> + value |= (num_rxq - 1) << GMAC_RXQCTRL_FPRQ_SHIFT;
> + writel(value, ioaddr + GMAC_RXQ_CTRL1);
> + } else {
> + cfg->fpe_csr = 0;
> }
> -
> - value = readl(ioaddr + GMAC_RXQ_CTRL1);
> - value &= ~GMAC_RXQCTRL_FPRQ;
> - value |= (num_rxq - 1) << GMAC_RXQCTRL_FPRQ_SHIFT;
> - writel(value, ioaddr + GMAC_RXQ_CTRL1);
> -
> - value = readl(ioaddr + MAC_FPE_CTRL_STS);
> - value |= EFPE;
> - writel(value, ioaddr + MAC_FPE_CTRL_STS);
> + writel(cfg->fpe_csr, ioaddr + MAC_FPE_CTRL_STS);
> }
>
> int dwmac5_fpe_irq_status(void __iomem *ioaddr, struct net_device *dev)
> @@ -741,6 +735,9 @@ int dwmac5_fpe_irq_status(void __iomem *ioaddr, struct net_device *dev)
>
> status = FPE_EVENT_UNKNOWN;
>
> + /* Reads from the MAC_FPE_CTRL_STS register should only be performed
> + * here, since the status flags of MAC_FPE_CTRL_STS are "clear on read"
> + */
> value = readl(ioaddr + MAC_FPE_CTRL_STS);
>
> if (value & TRSP) {
> @@ -766,19 +763,15 @@ int dwmac5_fpe_irq_status(void __iomem *ioaddr, struct net_device *dev)
> return status;
> }
>
> -void dwmac5_fpe_send_mpacket(void __iomem *ioaddr, enum stmmac_mpacket_type type)
> +void dwmac5_fpe_send_mpacket(void __iomem *ioaddr, struct stmmac_fpe_cfg *cfg,
> + enum stmmac_mpacket_type type)
> {
> - u32 value;
> + u32 value = cfg->fpe_csr;
>
> - value = readl(ioaddr + MAC_FPE_CTRL_STS);
> -
> - if (type == MPACKET_VERIFY) {
> - value &= ~SRSP;
> + if (type == MPACKET_VERIFY)
> value |= SVER;
> - } else {
> - value &= ~SVER;
> + else if (type == MPACKET_RESPONSE)
> value |= SRSP;
> - }
>
> writel(value, ioaddr + MAC_FPE_CTRL_STS);
> }
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac5.h b/drivers/net/ethernet/stmicro/stmmac/dwmac5.h
> index 53c138d..34e6207 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac5.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac5.h
> @@ -153,9 +153,11 @@ int dwmac5_est_configure(void __iomem *ioaddr, struct stmmac_est *cfg,
> unsigned int ptp_rate);
> void dwmac5_est_irq_status(void __iomem *ioaddr, struct net_device *dev,
> struct stmmac_extra_stats *x, u32 txqcnt);
> -void dwmac5_fpe_configure(void __iomem *ioaddr, u32 num_txq, u32 num_rxq,
> +void dwmac5_fpe_configure(void __iomem *ioaddr, struct stmmac_fpe_cfg *cfg,
> + u32 num_txq, u32 num_rxq,
> bool enable);
> void dwmac5_fpe_send_mpacket(void __iomem *ioaddr,
> + struct stmmac_fpe_cfg *cfg,
> enum stmmac_mpacket_type type);
> int dwmac5_fpe_irq_status(void __iomem *ioaddr, struct net_device *dev);
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
> index 453e88b..a74e71d 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
> @@ -1484,7 +1484,8 @@ static int dwxgmac3_est_configure(void __iomem *ioaddr, struct stmmac_est *cfg,
> return 0;
> }
>
> -static void dwxgmac3_fpe_configure(void __iomem *ioaddr, u32 num_txq,
> +static void dwxgmac3_fpe_configure(void __iomem *ioaddr, struct stmmac_fpe_cfg *cfg,
> + u32 num_txq,
> u32 num_rxq, bool enable)
> {
> u32 value;
> diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
> index b95d3e1..68aa2d5 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
> @@ -412,9 +412,11 @@ struct stmmac_ops {
> unsigned int ptp_rate);
> void (*est_irq_status)(void __iomem *ioaddr, struct net_device *dev,
> struct stmmac_extra_stats *x, u32 txqcnt);
> - void (*fpe_configure)(void __iomem *ioaddr, u32 num_txq, u32 num_rxq,
> + void (*fpe_configure)(void __iomem *ioaddr, struct stmmac_fpe_cfg *cfg,
> + u32 num_txq, u32 num_rxq,
> bool enable);
> void (*fpe_send_mpacket)(void __iomem *ioaddr,
> + struct stmmac_fpe_cfg *cfg,
> enum stmmac_mpacket_type type);
> int (*fpe_irq_status)(void __iomem *ioaddr, struct net_device *dev);
> };
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 3e50fd5..7791e9b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -964,7 +964,8 @@ static void stmmac_fpe_link_state_handle(struct stmmac_priv *priv, bool is_up)
> bool *hs_enable = &fpe_cfg->hs_enable;
>
> if (is_up && *hs_enable) {
> - stmmac_fpe_send_mpacket(priv, priv->ioaddr, MPACKET_VERIFY);
> + stmmac_fpe_send_mpacket(priv, priv->ioaddr, fpe_cfg,
> + MPACKET_VERIFY);
> } else {
> *lo_state = FPE_STATE_OFF;
> *lp_state = FPE_STATE_OFF;
> @@ -5838,6 +5839,7 @@ static void stmmac_fpe_event_status(struct stmmac_priv *priv, int status)
> /* If user has requested FPE enable, quickly response */
> if (*hs_enable)
> stmmac_fpe_send_mpacket(priv, priv->ioaddr,
> + fpe_cfg,
> MPACKET_RESPONSE);
> }
>
> @@ -7262,6 +7264,7 @@ static void stmmac_fpe_lp_task(struct work_struct *work)
> if (*lo_state == FPE_STATE_ENTERING_ON &&
> *lp_state == FPE_STATE_ENTERING_ON) {
> stmmac_fpe_configure(priv, priv->ioaddr,
> + fpe_cfg,
> priv->plat->tx_queues_to_use,
> priv->plat->rx_queues_to_use,
> *enable);
> @@ -7280,6 +7283,7 @@ static void stmmac_fpe_lp_task(struct work_struct *work)
> netdev_info(priv->dev, SEND_VERIFY_MPAKCET_FMT,
> *lo_state, *lp_state);
> stmmac_fpe_send_mpacket(priv, priv->ioaddr,
> + fpe_cfg,
> MPACKET_VERIFY);
> }
> /* Sleep then retry */
> @@ -7294,6 +7298,7 @@ void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable)
> if (priv->plat->fpe_cfg->hs_enable != enable) {
> if (enable) {
> stmmac_fpe_send_mpacket(priv, priv->ioaddr,
> + priv->plat->fpe_cfg,
> MPACKET_VERIFY);
> } else {
> priv->plat->fpe_cfg->lo_fpe_state = FPE_STATE_OFF;
> @@ -7754,6 +7759,7 @@ int stmmac_suspend(struct device *dev)
> if (priv->dma_cap.fpesel) {
> /* Disable FPE */
> stmmac_fpe_configure(priv, priv->ioaddr,
> + priv->plat->fpe_cfg,
> priv->plat->tx_queues_to_use,
> priv->plat->rx_queues_to_use, false);
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> index ac41ef4..6ad3e0a 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> @@ -1079,6 +1079,7 @@ static int tc_setup_taprio(struct stmmac_priv *priv,
>
> priv->plat->fpe_cfg->enable = false;
> stmmac_fpe_configure(priv, priv->ioaddr,
> + priv->plat->fpe_cfg,
> priv->plat->tx_queues_to_use,
> priv->plat->rx_queues_to_use,
> false);
> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> index 0b4658a..dee5ad6 100644
> --- a/include/linux/stmmac.h
> +++ b/include/linux/stmmac.h
> @@ -175,6 +175,7 @@ struct stmmac_fpe_cfg {
> bool hs_enable; /* FPE handshake enable */
> enum stmmac_fpe_state lp_fpe_state; /* Link Partner FPE state */
> enum stmmac_fpe_state lo_fpe_state; /* Local station FPE state */
> + u32 fpe_csr; /* MAC_FPE_CTRL_STS reg cache */
> };
>
> struct stmmac_safety_feature_cfg {
> --
> 1.8.3.1
>
>