Re: [PATCH net] net: ethernet: mediatek: Fix bit field in mtk_set_queue_speed()

[Dan Carpenter <dan.carpenter@linaro.org>]

On Mon, Mar 10, 2025 at 10:27:34PM +0300, Dan Carpenter wrote:
> On Mon, Mar 10, 2025 at 01:45:35PM +0100, Michal Kubiak wrote:
> > On Mon, Mar 10, 2025 at 01:48:27PM +0300, Dan Carpenter wrote:
> > > This was supposed to set "FIELD_PREP(MTK_QTX_SCH_MAX_RATE_WEIGHT, 1)"
> > > but there was typo and the | operation was missing and which turned
> > > it into a no-op.
> > > 
> > > Fixes: f63959c7eec3 ("net: ethernet: mtk_eth_soc: implement multi-queue support for per-port queues")
> > > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> > > ---
> > > From static analysis, not tested.
> > > 
> > >  drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > > index 922330b3f4d7..9efef0e860da 100644
> > > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > > @@ -757,7 +757,7 @@ static void mtk_set_queue_speed(struct mtk_eth *eth, unsigned int idx,
> > >  		case SPEED_100:
> > >  			val |= MTK_QTX_SCH_MAX_RATE_EN |
> > >  			       FIELD_PREP(MTK_QTX_SCH_MAX_RATE_MAN, 1) |
> > > -			       FIELD_PREP(MTK_QTX_SCH_MAX_RATE_EXP, 5);
> > > +			       FIELD_PREP(MTK_QTX_SCH_MAX_RATE_EXP, 5) |
> > >  			       FIELD_PREP(MTK_QTX_SCH_MAX_RATE_WEIGHT, 1);
> > >  			break;
> > >  		case SPEED_1000:
> > 
> > 
> > There's a similar bug a few lines above (line #737):
> > 
> > 	case SPEED_100:
> > 		val |= MTK_QTX_SCH_MAX_RATE_EN |
> > 		       FIELD_PREP(MTK_QTX_SCH_MAX_RATE_MAN, 103) |
> > 		       FIELD_PREP(MTK_QTX_SCH_MAX_RATE_EXP, 3);
> > 		       FIELD_PREP(MTK_QTX_SCH_MAX_RATE_WEIGHT, 1);
> > 		break;
> > 
> > I think it would be reasonable to fix that too in the same patch.
> 
> Yes.  You're of course correct.  I'm trying to figure out why my
> static checker found the one instance and not the other.  I will
> send a v2.

Oh...  Duh.  if (IS_ENABLED(CONFIG_SOC_MT7621)) is false for my config so
first line wasn't reachable.

regards,
dan carpenter