Re: [PATCH net-next v5 08/13] net: wwan: t7xx: Add data path interface

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Wed, 23 Feb 2022, Ricardo Martinez wrote:

> From: Haijun Liu <haijun.liu@mediatek.com>
> 
> Data Path Modem AP Interface (DPMAIF) HIF layer provides methods
> for initialization, ISR, control and event handling of TX/RX flows.
> 
> DPMAIF TX
> Exposes the `dmpaif_tx_send_skb` function which can be used by the
> network device to transmit packets.
> The uplink data management uses a Descriptor Ring Buffer (DRB).
> First DRB entry is a message type that will be followed by 1 or more
> normal DRB entries. Message type DRB will hold the skb information
> and each normal DRB entry holds a pointer to the skb payload.
> 
> DPMAIF RX
> The downlink buffer management uses Buffer Address Table (BAT) and
> Packet Information Table (PIT) rings.
> The BAT ring holds the address of skb data buffer for the HW to use,
> while the PIT contains metadata about a whole network packet including
> a reference to the BAT entry holding the data buffer address.
> The driver reads the PIT and BAT entries written by the modem, when
> reaching a threshold, the driver will reload the PIT and BAT rings.
> 
> Signed-off-by: Haijun Liu <haijun.liu@mediatek.com>
> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
> Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
> Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
> 
> >From a WWAN framework perspective:
> Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
> ---

> +static int t7xx_dpmaif_update_bat_wr_idx(struct dpmaif_ctrl *dpmaif_ctrl,
> +					 const unsigned char q_num, const unsigned int bat_cnt)
> +{
> +	struct dpmaif_rx_queue *rxq = &dpmaif_ctrl->rxq[q_num];
> +	unsigned short old_rl_idx, new_wr_idx, old_wr_idx;

unsigned int. I thought you listed a change for these idx local
variables but there were still many unsigned shorts. Please check
the whole change.

> +static int t7xx_dpmaif_rx_data_collect(struct dpmaif_ctrl *dpmaif_ctrl,
> +				       const unsigned char q_num, const unsigned int budget)
> +{
> +	struct dpmaif_rx_queue *rxq = &dpmaif_ctrl->rxq[q_num];
> +	unsigned long time_limit;
> +	unsigned int cnt;
> +
> +	time_limit = jiffies + msecs_to_jiffies(DPMAIF_WQ_TIME_LIMIT_MS);
> +
> +	while ((cnt = t7xx_dpmaifq_poll_pit(rxq))) {
> +		unsigned int rd_cnt;
> +		int real_cnt;
> +
> +		rd_cnt = min_t(unsigned int, cnt, budget);

This can be min(cnt, budget); because they're now both unsigned ints.
min_t is only needed if the args are of different type.

> +		t7xx_dpmaif_ul_update_hw_drb_cnt(&dpmaif_ctrl->hw_info, txq->index,
> +						 drb_send_cnt * DPMAIF_UL_DRB_SIZE_WORD);

This is the only callsite for t7xx_dpmaif_ul_update_hw_drb_cnt
that returns int (in 07). Change it to void?

> +		/* Wait for active Tx to be doneg */

doneg -> done.


-- 
 i.