Re: [PATCH net-next 10/19] net: hns: bugfix about pfc pause frame statistics

[Andy Shevchenko]

On Wed, 2016-06-22 at 09:43 +0800, Yisen Zhuang wrote:
> 
> å 2016/6/21 18:32, Andy Shevchenko åé:
> > On Tue, 2016-06-21 at 11:56 +0800, Yisen Zhuang wrote:
> > > From: Daode Huang <huangdaode@xxxxxxxxxxxxx>
> > > 
> > > For SoC hip06, PFC pause handled in dsaf, while hip05 in XGMAC,
> > > so change the statistics of pfc pause in dsaf and remove the old
> > > pfc pause frame statistics.
> > > 
> >Â
> > 
> > > +static char *hns_dsaf_get_node_stats_strings(char *data, int
> > > node,
> > > +					ÂÂÂÂÂstruct dsaf_device
> > > *dsaf_dev)
> > > Â{
> > > Â	char *buff = data;
> > > +	int i;
> > > +	bool is_ver1 = AE_IS_VER1(dsaf_dev->dsaf_ver);
> > > Â
> > > Â	snprintf(buff, ETH_GSTRING_LEN, "innod%d_pad_drop_pkts",
> > > node);
> > > Â	buff = buff + ETH_GSTRING_LEN;
> > > @@ -2502,6 +2530,18 @@ static char
> > > *hns_dsaf_get_node_stats_strings(char *data, int node)
> > > Â	buff = buff + ETH_GSTRING_LEN;
> > > Â	snprintf(buff, ETH_GSTRING_LEN, "innod%d_stp_drop_pkts",
> > > node);
> > > Â	buff = buff + ETH_GSTRING_LEN;
> > > +	if ((node < DSAF_SERVICE_NW_NUM) && (!is_ver1)) {
> > 
> > Redundant parens.
> > 
> > > +		for (i = 0; i < DSAF_PRIO_NR; i++) {
> > > +			snprintf(buff, ETH_GSTRING_LEN,
> > > +				Â"inod%d_pfc_prio%d_pkts", node,
> > > i);
> > > +			buff = buff + ETH_GSTRING_LEN;
> > 
> > buff += ...
> > 
> > > +		}
> > > +		for (i = 0; i < DSAF_PRIO_NR; i++) {
> > > +			snprintf(buff, ETH_GSTRING_LEN,
> > > +				Â"onod%d_pfc_prio%d_pkts", node,
> > > i);
> > > +			buff = buff + ETH_GSTRING_LEN;
> > 
> > Ditto.
> > 
> > > Â{
> > > Â	u64 *p = data;
> > > +	int i;
> > > Â	struct dsaf_hw_stats *hw_stats = &ddev-
> > > >hw_stats[node_num];
> > > +	bool is_ver1 = AE_IS_VER1(ddev->dsaf_ver);
> > > Â
> > > Â	p[0] = hw_stats->pad_drop;
> > > Â	p[1] = hw_stats->man_pkts;
> > > @@ -2527,8 +2569,16 @@ static u64 *hns_dsaf_get_node_stats(struct
> > > dsaf_device *ddev, u64 *data,
> > > Â	p[10] = hw_stats->local_addr_false;
> > > Â	p[11] = hw_stats->vlan_drop;
> > > Â	p[12] = hw_stats->stp_drop;
> > > -	p[13] = hw_stats->tx_pkts;
> > > +	if ((node_num < DSAF_SERVICE_NW_NUM) && (!is_ver1)) {
> > > +		for (i = 0; i < DSAF_PRIO_NR; i++) {
> > > +			p[13 + i] = hw_stats->rx_pfc[i];
> > > +			p[13 + i + DSAF_PRIO_NR] = hw_stats-
> > > > tx_pfc[i];
> > > +		}
> > 
> > Two different approaches how to assign data. Above uses 2 for-loops,
> > here you put everything to one.
> 
> Above cann't be merged to 1 for-loop, because lenght of the string is
> unknowable.

It doesn't matter since you are incrementing start position by
constant.Â

snprintf(buff, ETH_GSTRING_LEN, "inod%d_pfc_prio%d_pkts", node, i);
snprintf(buff, ETH_GSTRING_LEN, "onod%d_pfc_prio%d_pkts", node, i);

Same approach as below can be used

snprintf(buff + 0 * ETH_GSTRING_LEN * DSAF_PRIO_NR, ETH_GSTRING_LEN, ...
snprintf(buff + 1 * ETH_GSTRING_LEN * DSAF_PRIO_NR, ETH_GSTRING_LEN, ...

Of course to make it less verbose you may add new definition(s) and/ or
variable(s).

> 
> And here we put everything to one to reduce codes.
> 

I would suggest to use following pattern for such lines
p[13 + i + 0 * DSAF_PRIO_NR] = hw_stats->rx_pfc[i];
p[13 + i + 1 * DSAF_PRIO_NR] = hw_stats->tx_pfc[i];

That's allow reader to see what are you doing here.

P.S. This is for the future patches since current is already applied.

-- 

Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy