> -----Original Message----- > From: Benjamin Tissoires [mailto:benjamin.tissoires@xxxxxxxxxx] > Sent: Tuesday, September 23, 2014 8:12 AM > To: Jason Gerecke > Cc: linux-input@xxxxxxxxxxxxxxx; jkosina@xxxxxxx; pinglinux@xxxxxxxxx; > Jason Gerecke > Subject: Re: [PATCH] HID: input: Finish TransducerSerialNumber > implementation > > Hi Jason, > > On Sep 22 2014 or thereabouts, Jason Gerecke wrote: > > The commit which introduced TransducerSerialNumber (368c966) is > > missing two crucial implementation details. Firstly, the commit does > > not set the type/code/bit/max fields as expected later down the code > > which can cause the driver to crash when a tablet with this usage is > > connected. Secondly, the code to send a MSC_SERIAL event to userspace > > when this usage is seen in a report is nowhere to be found. This commit > addresses both issues. > > > > Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx> > > --- > > drivers/hid/hid-input.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index > > 2619f7f..abed624 100644 > > --- a/drivers/hid/hid-input.c > > +++ b/drivers/hid/hid-input.c > > @@ -690,6 +690,10 @@ static void hidinput_configure_usage(struct > > hid_input *hidinput, struct hid_fiel > > > > case 0x5b: /* TransducerSerialNumber */ > > set_bit(MSC_SERIAL, input->mscbit); > > + usage->type = EV_MSC; > > + usage->code = MSC_SERIAL; > > + bit = input->mscbit; > > + max = MSC_MAX; > > break; > > > > default: goto unknown; > > @@ -1041,6 +1045,11 @@ void hidinput_hid_event(struct hid_device *hid, > struct hid_field *field, struct > > input_event(input, EV_KEY, BTN_TOUCH, value > a + ((b - a) > >> 3)); > > } > > > > + if (usage->hid == (HID_UP_DIGITIZER | 0x005b)) { /* > TransducerSerialNumber */ > > + input_event(input, EV_MSC, MSC_SERIAL, value); > > + return; > > + } > > + > > Are you sure that the generic call to > "input_event(input, usage->type, usage->code, value);" in the end of > hidinput_hid_event() is not sufficient enough? > > As long as the usage/code are set in the hid_usage struct, you should be fine. > > Cheers, > Benjamin > Hmmm... This might be an issue with the HID descriptor, actually. It looks like my hardware doesn't set the logical minimum and maximum for the field, so the (quite out-of-range) value is ignored. I start seeing data after patching the descriptor to add these in, but the code is set to MSC_PULSELED instead of MSC_SERIAL. I suspect that the existing call to 'set_bit' in the TransducerSerialNumber case is to blame (which makes it act like 'map_foo' instead of 'map_foo_clear'). Updated patch forthcoming... Jason > > if (usage->hid == (HID_UP_PID | 0x83UL)) { /* Simultaneous Effects > Max */ > > dbg_hid("Maximum Effects - %d\n",value); > > return; > > -- > > 2.1.0 > > ��.n��������+%������w��{.n�����{��)��^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
