Re: [PATCH 2/2] hid: Don't sign-extend 16-bit values.

[Kai Krakow]

FWIW, this only shows on the horizontal axis, not the vertical. This makes
it even stranger...

Am So., 10. Feb. 2019, 22:04 hat Aric Stewart 
geschrieben:
> I am noticing this as well with one of my games and a ps4 pad. I have
> brought it up to Zeb but have not had a chance to dig.
>
> And my mirror problem did go away with this patch reverted.
>
> -aric
> > On Feb 10, 2019, at 1:10 PM, Kai Krakow  wrote:
> >
> > Hello again!
> >
> > I'm not sure if this commit is the problem, with it reverted I still
> > see strange effects: Moving the left stick only half-way right still
> > works correctly, moving it further turns it mirrored into left. Have
> > there been any other changes related to this? It worked fine in 4.0,
> > and the only other related change I could find here in my system was
> > updating from libSDL2-2.0.8 to 2.0.9 but I AFAIR this version still
> > worked with 4.0 correctly.
> >
> > Thanks,
> > Kai
> > > Am So., 10. Feb. 2019 um 19:02 Uhr schrieb Kai Krakow <[e-mail]
> >
> > :
> > > Hello!
> > >
> > > This change seems to introduce odd behavior in at least some games:
> > > Gamepad axis are mirrored to one side only now. This happens in Shadow
> > > of War (found by me) and Rocket League (reported by a user). I expect
> > > other games to fail in a similar way but didn't test those yet.
> > >
> > > I guess the clue is in "_may_ report a logical range"...
> > >
> > > I'm using the xpadneo driver with an Xbox One S wireless controller,
> > > and it reports -32768..32767 according to the driver (which follows
> > > the Linux spec on joysticks for this). This used to work perfectly
> > > before this change.
> > >
> > > Regards,
> > > Kai
> > > > Am Mi., 6. Feb. 2019 um 19:42 Uhr schrieb Aric Stewart <
>
> [e-mail]>:
> > > > Signed-off-by: Aric Stewart
> > > > > On 2/5/19 1:09 PM, Zebediah Figura wrote:
> > > > > From: Zebediah Figura
> > > > >
> > > > > Some controllers (including, with the previous patch, any reported
> > > > > through SDL) may report a logical range of [0,65535], which takes up
> > > > > 16 bits but should not be sign-extended.
> > > > > Signed-off-by: Zebediah Figura
> > > > >
> > > > > dlls/hid/hidp.c | 4 ----
> > > > >  1 file changed, 4 deletions(-)
> > > > >
> > > > > diff --git a/dlls/hid/hidp.c b/dlls/hid/hidp.c
> > > > > index f9978038e3..15d827edf1 100644
> > > > > --- a/dlls/hid/hidp.c
> > > > > +++ b/dlls/hid/hidp.c
> > > > > @@ -277,8 +277,6 @@ NTSTATUS WINAPI
>
> HidP_GetScaledUsageValue(HIDP_REPORT_TYPE ReportType, USAGE Usag
> > > > >                           element->valueStartBit,
>
> element->bitCount, &rawValue);
> > > > >      if (rc != HIDP_STATUS_SUCCESS)
> > > > >          return rc;
> > > > > -
> > > > >    if (element->caps.value.BitSize == 16)
> > > > > -
> > > > >        rawValue = (short)rawValue;
> > > > >    *UsageValue = rawValue;
> > > > > }
> > > > >
> > > > > @@ -925,8 +923,6 @@ NTSTATUS WINAPI HidP_GetData(HIDP_REPORT_TYPE
>
> ReportType, HIDP_DATA *DataList, U
> > > > >                                   element->valueStartBit,
>
> element->bitCount, &v);
> > > > >              if (rc != HIDP_STATUS_SUCCESS)
> > > > >                  return rc;
> > > > > -
> > > > >            if (element->caps.value.BitSize == 16)
> > > > > -
> > > > >                v = (short)v;
> > > > >            DataList[uCount].DataIndex =
>
> element->caps.value.u.NotRange.DataIndex;
> > > > >              DataList[uCount].u.RawValue = v;
> > > > >          }