Subject: Re: [PATCH v4 4/5] net: wan: fsl_qmc_hdlc: Add runtime timeslots changes support

From: Andy Shevchenko <[email-masked]>
Date: Thu, 22 Feb 2024 17:47:34 +0200

On Thu, Feb 22, 2024 at 03:22:17PM +0100, Herve Codina wrote:
> QMC channels support runtime timeslots changes but nothing is done at
> the QMC HDLC driver to handle these changes.
> 
> Use existing IFACE ioctl in order to configure the timeslots to use.

...

> +static int qmc_hdlc_xlate_slot_map(struct qmc_hdlc *qmc_hdlc,
> +				   u32 slot_map, struct qmc_chan_ts_info *ts_info)
> +{
> +	DECLARE_BITMAP(ts_mask_avail, 64);
> +	DECLARE_BITMAP(ts_mask, 64);
> +	DECLARE_BITMAP(map, 64);

Perhaps more 1:1 naming?

	DECLARE_BITMAP(rx_ts_mask_avail, 64);
	DECLARE_BITMAP(tx_ts_mask, 64);
	DECLARE_BITMAP(slot_map, 64);

> +	/* Tx and Rx available masks must be identical */
> +	if (ts_info->rx_ts_mask_avail != ts_info->tx_ts_mask_avail) {
> +		dev_err(qmc_hdlc->dev, "tx and rx available timeslots mismatch (0x%llx, 0x%llx)\n",
> +			ts_info->rx_ts_mask_avail, ts_info->tx_ts_mask_avail);
> +		return -EINVAL;
> +	}
> +
> +	bitmap_from_u64(ts_mask_avail, ts_info->rx_ts_mask_avail);
> +	bitmap_from_u64(map, slot_map);
> +	bitmap_scatter(ts_mask, map, ts_mask_avail, 64);
> +
> +	if (bitmap_weight(ts_mask, 64) != bitmap_weight(map, 64)) {
> +		dev_err(qmc_hdlc->dev, "Cannot translate timeslots %*pb -> (%*pb, %*pb)\n",
> +			64, map, 64, ts_mask_avail, 64, ts_mask);

You can save a bit of code and stack:

		dev_err(qmc_hdlc->dev, "Cannot translate timeslots %64pb -> (%64pb, %64pb)\n",
			slot_map, rx_ts_mask_avail, tx_ts_mask);

> +		return -EINVAL;
> +	}
> +
> +	bitmap_to_arr64(&ts_info->tx_ts_mask, ts_mask, 64);
> +	ts_info->rx_ts_mask = ts_info->tx_ts_mask;
> +	return 0;
> +}

...

> +static int qmc_hdlc_xlate_ts_info(struct qmc_hdlc *qmc_hdlc,
> +				  const struct qmc_chan_ts_info *ts_info, u32 *slot_map)

Similar comments apply as per above function.

...

> +	ret = qmc_chan_get_ts_info(qmc_hdlc->qmc_chan, &ts_info);
> +	if (ret) {
> +		dev_err(qmc_hdlc->dev, "get QMC channel ts info failed %d\n", ret);
> +		return ret;

		return dev_err_probe(...);

> +	}

-- 
With Best Regards,
Andy Shevchenko