From: Richard Cochran <richardcochran@gmail.com>
To: Wong Vee Khee <vee.khee.wong@linux.intel.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>,
Alexandre Torgue <alexandre.torgue@st.com>,
Jose Abreu <joabreu@synopsys.com>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Voon Weifeng <weifeng.voon@intel.com>,
Ong Boon Leong <boon.leong.ong@intel.com>,
netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next v3 1/1] net: stmmac: Add support for external trigger timestamping
Date: Sun, 11 Apr 2021 08:10:55 -0700 [thread overview]
Message-ID: <20210411151055.GA5719@hoboy.vegasvil.org> (raw)
In-Reply-To: <20210411024028.14586-1-vee.khee.wong@linux.intel.com>
On Sun, Apr 11, 2021 at 10:40:28AM +0800, Wong Vee Khee wrote:
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
> index 60566598d644..60e17fd24aba 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
> @@ -296,6 +296,13 @@ static int intel_crosststamp(ktime_t *device,
>
> intel_priv = priv->plat->bsp_priv;
>
> + /* Both internal crosstimestamping and external triggered event
> + * timestamping cannot be run concurrently.
> + */
> + if (priv->plat->ext_snapshot_en)
> + return -EBUSY;
> +
> + mutex_lock(&priv->aux_ts_lock);
Lock, then ...
> /* Enable Internal snapshot trigger */
> acr_value = readl(ptpaddr + PTP_ACR);
> acr_value &= ~PTP_ACR_MASK;
> @@ -321,6 +328,7 @@ static int intel_crosststamp(ktime_t *device,
> acr_value = readl(ptpaddr + PTP_ACR);
> acr_value |= PTP_ACR_ATSFC;
> writel(acr_value, ptpaddr + PTP_ACR);
> + mutex_unlock(&priv->aux_ts_lock);
unlock, then ...
> /* Trigger Internal snapshot signal
> * Create a rising edge by just toggle the GPO1 to low
> @@ -355,6 +363,8 @@ static int intel_crosststamp(ktime_t *device,
> *system = convert_art_to_tsc(art_time);
> }
>
> + /* Release the mutex */
> + mutex_unlock(&priv->aux_ts_lock);
unlock again? Huh?
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> index c49debb62b05..abadcd8cdc41 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> @@ -239,6 +239,9 @@ struct stmmac_priv {
> int use_riwt;
> int irq_wake;
> spinlock_t ptp_lock;
> + /* Mutex lock for Auxiliary Snapshots */
> + struct mutex aux_ts_lock;
In the comment, please be specific about which data are protected.
For example:
/* Protects auxiliary snapshot registers from concurrent access. */
> @@ -163,6 +166,43 @@ static void get_ptptime(void __iomem *ptpaddr, u64 *ptp_time)
> *ptp_time = ns;
> }
>
> +static void timestamp_interrupt(struct stmmac_priv *priv)
> +{
> + struct ptp_clock_event event;
> + unsigned long flags;
> + u32 num_snapshot;
> + u32 ts_status;
> + u32 tsync_int;
Please group same types together (u32) in a one-line list.
> + u64 ptp_time;
> + int i;
> +
> + tsync_int = readl(priv->ioaddr + GMAC_INT_STATUS) & GMAC_INT_TSIE;
> +
> + if (!tsync_int)
> + return;
> +
> + /* Read timestamp status to clear interrupt from either external
> + * timestamp or start/end of PPS.
> + */
> + ts_status = readl(priv->ioaddr + GMAC_TIMESTAMP_STATUS);
Reading this register has a side effect of clearing status? If so,
doesn't it need protection against concurrent access?
The function, intel_crosststamp() also reads this bit.
> + if (!priv->plat->ext_snapshot_en)
> + return;
Doesn't this test come too late? Setting ts_status just cleared the
bit used by the other code path.
> + num_snapshot = (ts_status & GMAC_TIMESTAMP_ATSNS_MASK) >>
> + GMAC_TIMESTAMP_ATSNS_SHIFT;
> +
> + for (i = 0; i < num_snapshot; i++) {
> + spin_lock_irqsave(&priv->ptp_lock, flags);
> + get_ptptime(priv->ptpaddr, &ptp_time);
> + spin_unlock_irqrestore(&priv->ptp_lock, flags);
> + event.type = PTP_CLOCK_EXTTS;
> + event.index = 0;
> + event.timestamp = ptp_time;
> + ptp_clock_event(priv->ptp_clock, &event);
> + }
> +}
> +
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
> index b164ae22e35f..d668c33a0746 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
> @@ -135,9 +135,13 @@ static int stmmac_enable(struct ptp_clock_info *ptp,
> {
> struct stmmac_priv *priv =
> container_of(ptp, struct stmmac_priv, ptp_clock_ops);
> + void __iomem *ptpaddr = priv->ptpaddr;
> + void __iomem *ioaddr = priv->hw->pcsr;
> struct stmmac_pps_cfg *cfg;
> int ret = -EOPNOTSUPP;
> unsigned long flags;
> + u32 intr_value;
> + u32 acr_value;
Please group same types together.
Thanks,
Richard
next prev parent reply other threads:[~2021-04-11 15:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-11 2:40 [PATCH net-next v3 1/1] net: stmmac: Add support for external trigger timestamping Wong Vee Khee
2021-04-11 15:10 ` Richard Cochran [this message]
2021-04-13 5:07 ` Wong Vee Khee
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