| Message ID | 20190318145024.GA572@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 22feda47b574c2854cc1a8447a2ae18598752375 |
| Headers | show |
| Series | usb: usb251xb: Remove unnecessary comparison of unsigned integer with >= 0 | expand |
Hi Silva, On 19-03-18 09:50, Gustavo A. R. Silva wrote: > There is no need to compare *port* with >= 0 because such comparison > of an unsigned value is always true. Absolutly.. It seems that it was an copy'n'paste failure. Thanks for fixing that. Regards, Marco > Fix this by removing such comparison. > > Addresses-Coverity-ID: 1443949 ("Unsigned compared against 0") > Fixes: 02a50b875046 ("usb: usb251xb: add usb data lane port swap feature") > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > drivers/usb/misc/usb251xb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/misc/usb251xb.c b/drivers/usb/misc/usb251xb.c > index 4d72b7d1d383..2c8e2cad7e10 100644 > --- a/drivers/usb/misc/usb251xb.c > +++ b/drivers/usb/misc/usb251xb.c > @@ -547,7 +547,7 @@ static int usb251xb_get_ofdata(struct usb251xb *hub, > */ > hub->port_swap = USB251XB_DEF_PORT_SWAP; > of_property_for_each_u32(np, "swap-dx-lanes", prop, p, port) { > - if ((port >= 0) && (port <= data->port_cnt)) > + if (port <= data->port_cnt) > hub->port_swap |= BIT(port); > } > > -- > 2.21.0 > >
Hi Marco, Hi Gustavo, thanks for the fix, please feel free to add Reviewed-by: Richard Leitner <richard.leitner@skidata.com> On 18/03/2019 16:34, Marco Felsch wrote: > Hi Silva, > > On 19-03-18 09:50, Gustavo A. R. Silva wrote: >> There is no need to compare *port* with >= 0 because such comparison >> of an unsigned value is always true. > > Absolutly.. It seems that it was an copy'n'paste failure. Thanks for > fixing that. A small note on further improvement from my side: According the datasheet, when you set swap-dx-lanes to 0 (-> setting port to 0 -> setting bit 0 of PRTSP) " the upstream port DP/DM is swapped". IMHO this is not straight-forward, so maybe we want to additionally a) mention it somewhere in the documentation b) check on port >= 1 c) something else? Any opinions on that from your side? ... I'd prefer "a"... regards;Richard.L > > Regards, > Marco > >> Fix this by removing such comparison. >> >> Addresses-Coverity-ID: 1443949 ("Unsigned compared against 0") >> Fixes: 02a50b875046 ("usb: usb251xb: add usb data lane port swap feature") >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> >> --- >> drivers/usb/misc/usb251xb.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/usb/misc/usb251xb.c b/drivers/usb/misc/usb251xb.c >> index 4d72b7d1d383..2c8e2cad7e10 100644 >> --- a/drivers/usb/misc/usb251xb.c >> +++ b/drivers/usb/misc/usb251xb.c >> @@ -547,7 +547,7 @@ static int usb251xb_get_ofdata(struct usb251xb *hub, >> */ >> hub->port_swap = USB251XB_DEF_PORT_SWAP; >> of_property_for_each_u32(np, "swap-dx-lanes", prop, p, port) { >> - if ((port >= 0) && (port <= data->port_cnt)) >> + if (port <= data->port_cnt) >> hub->port_swap |= BIT(port); >> } >> >> -- >> 2.21.0 >> >> >
Hi Richard, On 19-03-18 16:46, Richard Leitner wrote: > Hi Marco, Hi Gustavo, > thanks for the fix, please feel free to add > > Reviewed-by: Richard Leitner <richard.leitner@skidata.com> > > On 18/03/2019 16:34, Marco Felsch wrote: > > Hi Silva, > > > > On 19-03-18 09:50, Gustavo A. R. Silva wrote: > > > There is no need to compare *port* with >= 0 because such comparison > > > of an unsigned value is always true. > > > > Absolutly.. It seems that it was an copy'n'paste failure. Thanks for > > fixing that. > > A small note on further improvement from my side: > > According the datasheet, when you set swap-dx-lanes to 0 (-> setting port to > 0 -> setting bit 0 of PRTSP) " the upstream port DP/DM is swapped". Yes I know that's not intuitve and may confuses the users. > IMHO this is not straight-forward, so maybe we want to additionally > > a) mention it somewhere in the documentation IMHO this is the correct place. > b) check on port >= 1 I think this isn't doable since we shouldn't break the existing dt. Regards, Marco > c) something else? > > Any opinions on that from your side? ... I'd prefer "a"... > > regards;Richard.L > > > > > Regards, > > Marco > > > > > Fix this by removing such comparison. > > > > > > Addresses-Coverity-ID: 1443949 ("Unsigned compared against 0") > > > Fixes: 02a50b875046 ("usb: usb251xb: add usb data lane port swap feature") > > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > > > --- > > > drivers/usb/misc/usb251xb.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/usb/misc/usb251xb.c b/drivers/usb/misc/usb251xb.c > > > index 4d72b7d1d383..2c8e2cad7e10 100644 > > > --- a/drivers/usb/misc/usb251xb.c > > > +++ b/drivers/usb/misc/usb251xb.c > > > @@ -547,7 +547,7 @@ static int usb251xb_get_ofdata(struct usb251xb *hub, > > > */ > > > hub->port_swap = USB251XB_DEF_PORT_SWAP; > > > of_property_for_each_u32(np, "swap-dx-lanes", prop, p, port) { > > > - if ((port >= 0) && (port <= data->port_cnt)) > > > + if (port <= data->port_cnt) > > > hub->port_swap |= BIT(port); > > > } > > > -- > > > 2.21.0 > > > > > > > > >
On 18/03/2019 17:48, Marco Felsch wrote: > On 19-03-18 16:46, Richard Leitner wrote: >> A small note on further improvement from my side: >> >> According the datasheet, when you set swap-dx-lanes to 0 (-> setting port to >> 0 -> setting bit 0 of PRTSP) " the upstream port DP/DM is swapped". > > Yes I know that's not intuitve and may confuses the users. > >> IMHO this is not straight-forward, so maybe we want to additionally >> >> a) mention it somewhere in the documentation > > IMHO this is the correct place. > >> b) check on port >= 1 > > I think this isn't doable since we shouldn't break the existing dt. ACK. @Marco/Gustavo: does one of you wants to provide a patch for this? > > Regards, > Marco > >> c) something else? >> >> Any opinions on that from your side? ... I'd prefer "a"... regards;Richard.L
diff --git a/drivers/usb/misc/usb251xb.c b/drivers/usb/misc/usb251xb.c index 4d72b7d1d383..2c8e2cad7e10 100644 --- a/drivers/usb/misc/usb251xb.c +++ b/drivers/usb/misc/usb251xb.c @@ -547,7 +547,7 @@ static int usb251xb_get_ofdata(struct usb251xb *hub, */ hub->port_swap = USB251XB_DEF_PORT_SWAP; of_property_for_each_u32(np, "swap-dx-lanes", prop, p, port) { - if ((port >= 0) && (port <= data->port_cnt)) + if (port <= data->port_cnt) hub->port_swap |= BIT(port); }
There is no need to compare *port* with >= 0 because such comparison of an unsigned value is always true. Fix this by removing such comparison. Addresses-Coverity-ID: 1443949 ("Unsigned compared against 0") Fixes: 02a50b875046 ("usb: usb251xb: add usb data lane port swap feature") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/usb/misc/usb251xb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)