Re: [PATCH net-next v2 8/9] ptp_ocp: implement DPLL ops

[Simon Horman <horms@kernel.org>]

On Fri, Aug 04, 2023 at 08:04:53PM +0100, Vadim Fedorenko wrote:
> Implement basic DPLL operations in ptp_ocp driver as the
> simplest example of using new subsystem.
> 
> Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
> Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>

Hi Vadim,

...

> diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
> index 32dff1b4f891..e4da62ac9a9f 100644
> --- a/drivers/ptp/Kconfig
> +++ b/drivers/ptp/Kconfig
> @@ -177,6 +177,7 @@ config PTP_1588_CLOCK_OCP
>  	depends on COMMON_CLK
>  	select NET_DEVLINK
>  	select CRC16
> +	select DPLL
>  	help
>  	  This driver adds support for an OpenCompute time card.
>  
> diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c

...

> +static int ptp_ocp_dpll_frequency_set(const struct dpll_pin *pin,
> +				      void *pin_priv,
> +				      const struct dpll_device *dpll,
> +				      void *dpll_priv, u64 frequency,
> +				      struct netlink_ext_ack *extack)
> +{
> +	struct ptp_ocp_sma_connector *sma = pin_priv;
> +	struct ptp_ocp *bp = dpll_priv;
> +	const struct ocp_selector *tbl;
> +	int sma_nr = (sma - bp->sma);
> +	int val, i;
> +
> +	if (sma->fixed_fcn)
> +		return -EOPNOTSUPP;
> +
> +	tbl = bp->sma_op->tbl[sma->mode];
> +	for (i = 0; tbl[i].name; i++)
> +		if (tbl[i].frequency == frequency)
> +			return ptp_ocp_sma_store_val(bp, val, sma->mode, sma_nr);

val appears to be used uninitialised here.

As flagged by clang-16 W=1, and Smatch.

> +	return -EINVAL;
> +}

...

> @@ -4233,8 +4437,40 @@ ptp_ocp_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  
>  	ptp_ocp_info(bp);
>  	devlink_register(devlink);
> -	return 0;
>  
> +	clkid = pci_get_dsn(pdev);
> +	bp->dpll = dpll_device_get(clkid, 0, THIS_MODULE);
> +	if (IS_ERR(bp->dpll)) {
> +		dev_err(&pdev->dev, "dpll_device_alloc failed\n");
> +		goto out;
> +	}
> +
> +	err = dpll_device_register(bp->dpll, DPLL_TYPE_PPS, &dpll_ops, bp);
> +	if (err)
> +		goto out;
> +
> +	for (i = 0; i < OCP_SMA_NUM; i++) {
> +		bp->sma[i].dpll_pin = dpll_pin_get(clkid, i, THIS_MODULE, &bp->sma[i].dpll_prop);
> +		if (IS_ERR(bp->sma[i].dpll_pin))

The function will return err.
Should it be sett to an error value here?

As flagged by Smatch.

> +			goto out_dpll;
> +
> +		err = dpll_pin_register(bp->dpll, bp->sma[i].dpll_pin, &dpll_pins_ops,
> +					&bp->sma[i]);
> +		if (err) {
> +			dpll_pin_put(bp->sma[i].dpll_pin);
> +			goto out_dpll;
> +		}
> +	}
> +	queue_delayed_work(system_power_efficient_wq, &bp->sync_work, HZ);
> +
> +	return 0;
> +out_dpll:
> +	while (i) {
> +		--i;
> +		dpll_pin_unregister(bp->dpll, bp->sma[i].dpll_pin, &dpll_pins_ops, &bp->sma[i]);
> +		dpll_pin_put(bp->sma[i].dpll_pin);
> +	}
> +	dpll_device_put(bp->dpll);
>  out:
>  	ptp_ocp_detach(bp);
>  out_disable:

...