| Message ID | 20211202083541.2025-2-aaron.ma@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix cursor jump issue of Elan Trackpoint on ThinkPad AMD | expand |
On 02.12.21 09:35, Aaron Ma wrote: > From: Phoenix Huang <phoenix@emc.com.tw> > > BugLink: https://bugs.launchpad.net/bugs/1936295 > > Some firmwares occasionally report bogus data from trackpoint, with X or Y > displacement being too large (outside of [-127, 127] range). Let's drop such > packets so that we do not generate jumps. > > Signed-off-by: Phoenix Huang <phoenix@emc.com.tw> > Tested-by: Yufei Du <yufeidu@cs.unc.edu> > Link: https://lore.kernel.org/r/20210729010940.5752-1-phoenix@emc.com.tw > Cc: stable@vger.kernel.org > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > (cherry picked from commit be896bd3b72b44126c55768f14c22a8729b0992e) > Signed-off-by: Aaron Ma <aaron.ma@canonical.com> Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> Thanks > --- > drivers/input/mouse/elantech.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > index 2d0bc029619f..956d9cd34796 100644 > --- a/drivers/input/mouse/elantech.c > +++ b/drivers/input/mouse/elantech.c > @@ -517,6 +517,19 @@ static void elantech_report_trackpoint(struct psmouse *psmouse, > case 0x16008020U: > case 0x26800010U: > case 0x36808000U: > + > + /* > + * This firmware misreport coordinates for trackpoint > + * occasionally. Discard packets outside of [-127, 127] range > + * to prevent cursor jumps. > + */ > + if (packet[4] == 0x80 || packet[5] == 0x80 || > + packet[1] >> 7 == packet[4] >> 7 || > + packet[2] >> 7 == packet[5] >> 7) { > + elantech_debug("discarding packet [%6ph]\n", packet); > + break; > + > + } > x = packet[4] - (int)((packet[1]^0x80) << 1); > y = (int)((packet[2]^0x80) << 1) - packet[5]; >
On 02.12.21 09:35, Aaron Ma wrote: > From: Phoenix Huang <phoenix@emc.com.tw> > > BugLink: https://bugs.launchpad.net/bugs/1936295 > > Some firmwares occasionally report bogus data from trackpoint, with X or Y > displacement being too large (outside of [-127, 127] range). Let's drop such > packets so that we do not generate jumps. > > Signed-off-by: Phoenix Huang <phoenix@emc.com.tw> > Tested-by: Yufei Du <yufeidu@cs.unc.edu> > Link: https://lore.kernel.org/r/20210729010940.5752-1-phoenix@emc.com.tw > Cc: stable@vger.kernel.org > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > (cherry picked from commit be896bd3b72b44126c55768f14c22a8729b0992e) > Signed-off-by: Aaron Ma <aaron.ma@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- > drivers/input/mouse/elantech.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > index 2d0bc029619f..956d9cd34796 100644 > --- a/drivers/input/mouse/elantech.c > +++ b/drivers/input/mouse/elantech.c > @@ -517,6 +517,19 @@ static void elantech_report_trackpoint(struct psmouse *psmouse, > case 0x16008020U: > case 0x26800010U: > case 0x36808000U: > + > + /* > + * This firmware misreport coordinates for trackpoint > + * occasionally. Discard packets outside of [-127, 127] range > + * to prevent cursor jumps. > + */ > + if (packet[4] == 0x80 || packet[5] == 0x80 || > + packet[1] >> 7 == packet[4] >> 7 || > + packet[2] >> 7 == packet[5] >> 7) { > + elantech_debug("discarding packet [%6ph]\n", packet); > + break; > + > + } > x = packet[4] - (int)((packet[1]^0x80) << 1); > y = (int)((packet[2]^0x80) << 1) - packet[5]; > >
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index 2d0bc029619f..956d9cd34796 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -517,6 +517,19 @@ static void elantech_report_trackpoint(struct psmouse *psmouse, case 0x16008020U: case 0x26800010U: case 0x36808000U: + + /* + * This firmware misreport coordinates for trackpoint + * occasionally. Discard packets outside of [-127, 127] range + * to prevent cursor jumps. + */ + if (packet[4] == 0x80 || packet[5] == 0x80 || + packet[1] >> 7 == packet[4] >> 7 || + packet[2] >> 7 == packet[5] >> 7) { + elantech_debug("discarding packet [%6ph]\n", packet); + break; + + } x = packet[4] - (int)((packet[1]^0x80) << 1); y = (int)((packet[2]^0x80) << 1) - packet[5];