Re: [PATCH net-next 2/3] cxgb4: Add PTP Hardware Clock (PHC) support

[Richard Cochran <richardcochran@gmail.com>]

On Tue, Jul 04, 2017 at 04:46:21PM +0530, Atul Gupta wrote:
> +/**
> + * cxgb4_ptp_init - initialize PTP for devices which support it
> + * @adapter: board private structure
> + *
> + * This function performs the required steps for enabling PTP support.
> + */
> +void cxgb4_ptp_init(struct adapter *adapter)
> +{
> +	struct timespec64 now;
> +	 /* no need to create a clock device if we already have one */
> +	if (!IS_ERR_OR_NULL(adapter->ptp_clock))
> +		return;
> +
> +	adapter->ptp_tx_skb = NULL;
> +	adapter->ptp_clock_info = cxgb4_ptp_clock_info;
> +	spin_lock_init(&adapter->ptp_lock);
> +
> +	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
> +						&adapter->pdev->dev);
> +	if (!adapter->ptp_clock) {
> +		dev_err(adapter->pdev_dev,
> +			"PTP %s Clock registration has failed\n", __func__);
> +		return;
> +	}

This is wrong.  To quote the header file:

/**
 * ptp_clock_register() - register a PTP hardware clock driver
 *
 * @info:   Structure describing the new clock.
 * @parent: Pointer to the parent device of the new clock.
 *
 * Returns a valid pointer on success or PTR_ERR on failure.  If PHC
 * support is missing at the configuration level, this function
 * returns NULL, and drivers are expected to gracefully handle that
 * case separately.
 */

As this has already been merged, please submit a patch to properly
handle both PTR_ERR and NULL.

Thanks,
Richard