On Thu, Dec 07, 2017 at 02:50:24PM -0500, David Miller wrote: > From: Ivan Khoronzhuk <ivan.khoronz...@linaro.org> > Date: Thu, 7 Dec 2017 21:48:56 +0200 > > > On Wed, Dec 06, 2017 at 04:35:45PM -0500, David Miller wrote: > >> From: Ivan Khoronzhuk <ivan.khoronz...@linaro.org> > >> Date: Wed, 6 Dec 2017 16:41:18 +0200 > >> > >> > If rate is the same as set it's correct case. > >> > > >> > Signed-off-by: Ivan Khoronzhuk <ivan.khoronz...@linaro.org> > >> > --- > >> > Based on net-next/master > >> > > >> > drivers/net/ethernet/ti/davinci_cpdma.c | 2 +- > >> > 1 file changed, 1 insertion(+), 1 deletion(-) > >> > > >> > diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c > >> > b/drivers/net/ethernet/ti/davinci_cpdma.c > >> > index e4d6edf..dbe9167 100644 > >> > --- a/drivers/net/ethernet/ti/davinci_cpdma.c > >> > +++ b/drivers/net/ethernet/ti/davinci_cpdma.c > >> > @@ -841,7 +841,7 @@ int cpdma_chan_set_rate(struct cpdma_chan *ch, u32 > >> > rate) > >> > return -EINVAL; > >> > > >> > if (ch->rate == rate) > >> > - return rate; > >> > + return 0; > >> > >> Looking at the one and only caller of this function, > >> cpsw_ndo_set_tx_maxrate, it > >> makes sure this can never, ever, happen. > > In current circumstances yes, it will never happen. > > But I caught it while adding related code and better return 0 if upper > > caller > > doesn't have such check. Suppose that cpdma module is responsible for itself > > and if it's critical I can send this patch along with whole related series. > > You have to decide one way or the other, who is responsible. > > I think checking higher up is better because it's cheaper at that point to > look at the per-netdev queue rate setting before moving down deeper into the > driver specific data-structures.
No objection, but upper caller not always knows current rate and for doing like this it needs read it first, and this is also some redundancy. -- Regards, Ivan Khoronzhuk
