Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization

From: Richard Cochran
Date: Wed Sep 14 2016 - 09:52:25 EST


On Wed, Sep 14, 2016 at 04:02:25PM +0300, Grygorii Strashko wrote:
> @@ -323,7 +307,7 @@ void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
> u64 ns;
> struct skb_shared_hwtstamps *ssh;
>
> - if (!cpts->rx_enable)
> + if (!cpts || !cpts->rx_enable)
> return;

This function is in the hot path, and you have added a pointless new
test. Don't do that.

> ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
> if (!ns)
> @@ -338,7 +322,7 @@ void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
> u64 ns;
> struct skb_shared_hwtstamps ssh;
>
> - if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
> + if (!cpts || !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
> return;

Same here.

> ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
> if (!ns)
> @@ -348,53 +332,102 @@ void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
> skb_tstamp_tx(skb, &ssh);
> }
>
> -int cpts_register(struct device *dev, struct cpts *cpts,
> - u32 mult, u32 shift)
> +int cpts_register(struct cpts *cpts)
> {
> int err, i;
> - unsigned long flags;
>
> - cpts->info = cpts_info;
> - cpts->clock = ptp_clock_register(&cpts->info, dev);
> - if (IS_ERR(cpts->clock)) {
> - err = PTR_ERR(cpts->clock);
> - cpts->clock = NULL;
> - return err;
> - }
> - spin_lock_init(&cpts->lock);
> -
> - cpts->cc.read = cpts_systim_read;
> - cpts->cc.mask = CLOCKSOURCE_MASK(32);
> - cpts->cc_mult = mult;
> - cpts->cc.mult = mult;
> - cpts->cc.shift = shift;
> + if (!cpts)
> + return -EINVAL;

Not hot path, but still silly. The caller should never pass NULL.

Thanks,
Richard