On Wed, Feb 16, 2022 at 4:43 AM Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> wrote: > > Hi Ping, > > [bringing back the public ML] > > On Tue, Feb 15, 2022 at 9:51 AM Benjamin Tissoires > <benjamin.tissoires@xxxxxxxxxx> wrote: > > > > On Tue, Feb 15, 2022 at 3:04 AM Ping Cheng <pinglinux@xxxxxxxxx> wrote: > > > > > > On Mon, Feb 14, 2022 at 2:23 AM Benjamin Tissoires > > > <benjamin.tissoires@xxxxxxxxxx> wrote: > > > > > > > > Hi Ping, > > > > > > > > On Thu, Feb 10, 2022 at 6:44 AM Ping Cheng <pinglinux@xxxxxxxxx> wrote: > > > > > > > > > > Sorry for the noise. Hit the wrong buttons... > > > > > > > > > > On Wed, Feb 9, 2022 at 9:21 PM Ping Cheng <pinglinux@xxxxxxxxx> wrote: > > > > > > > > > > > > On Thu, Feb 3, 2022 at 6:33 AM Benjamin Tissoires > > > > > > <benjamin.tissoires@xxxxxxxxxx> wrote: > > > > > > > > > > > > > > HID_QUIRK_INVERT is kind of complex to deal with and was bogus. > > > > > > > > > > > > > > Furthermore, it didn't make sense to use a global per struct hid_device > > > > > > > quirk for something dynamic as the current state. > > > > > > > > > > > > > > Store the current tool information in the report itself, and re-order > > > > > > > the processing of the fields to enforce having all the tablet "state" > > > > > > > fields before getting to In Range and other input fields. > > > > > > > > > > > > > > This way, we now have all the information whether a tool is present > > > > > > > or not while processing In Range. > > > > > > > > > > > > > > This new behavior enforces that only one tool gets forwarded to userspace > > > > > > > at the same time, and that if either eraser or invert is set, we enforce > > > > > > > BTN_TOOL_RUBBER. > > > > > > > > > > > > > > Note that the release of the previous tool now happens in its own EV_SYN > > > > > > > report so userspace doesn't get confused by having 2 tools. > > > > > > > > > > > > > > These changes are tested in the following hid-tools regression tests: > > > > > > > https://gitlab.freedesktop.org/libevdev/hid-tools/-/merge_requests/127 > > > > > > > > > > > > > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > Changes in v2: > > > > > > > - rework the entire tool switching, this makes the processing > > > > > > > slightly more complex but is better for existing userspace. > > > > > > > --- > > > > > > > drivers/hid/hid-input.c | 98 +++++++++++++++++++++++++++++++++++++---- > > > > > > > include/linux/hid.h | 6 ++- > > > > > > > 2 files changed, 95 insertions(+), 9 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c > > > > > > > index 61d91117f4ae..9f8853640648 100644 > > > > > > > --- a/drivers/hid/hid-input.c > > > > > > > +++ b/drivers/hid/hid-input.c > > > > > > > @@ -63,8 +63,11 @@ static const struct { > > > > > > > * This still leaves us 65535 individual priority values. > > > > > > > */ > > > > > > > static const __u32 hidinput_usages_priorities[] = { > > > > > > > + HID_DG_ERASER, /* Eraser (eraser touching) must always come before tipswitch */ > > > > > > > HID_DG_INVERT, /* Invert must always come before In Range */ > > > > > > > - HID_DG_INRANGE, > > > > > > > + HID_DG_TIPSWITCH, /* Is the tip of the tool touching? */ > > > > > > > + HID_DG_TIPPRESSURE, /* Tip Pressure might emulate tip switch */ > > > > > > > + HID_DG_INRANGE, /* In Range needs to come after the other tool states */ > > > > > > > }; > > > > > > > > > > > > > > #define map_abs(c) hid_map_usage(hidinput, usage, &bit, &max, EV_ABS, (c)) > > > > > > > @@ -1365,9 +1368,38 @@ static void hidinput_handle_scroll(struct hid_usage *usage, > > > > > > > input_event(input, EV_REL, usage->code, hi_res); > > > > > > > } > > > > > > > > > > > > > > +static void hid_report_release_tool(struct hid_report *report, struct input_dev *input, > > > > > > > + unsigned int tool) > > > > > > > +{ > > > > > > > + /* if the given tool is not currently reported, ignore */ > > > > > > > + if (!test_bit(tool, input->key)) > > > > > > > + return; > > > > > > > + > > > > > > > + /* > > > > > > > + * if the given tool was previously set, release it, > > > > > > > + * release any TOUCH and send an EV_SYN > > > > > > > + */ > > > > > > > + input_event(input, EV_KEY, BTN_TOUCH, 0); > > > > > > > + input_event(input, EV_KEY, tool, 0); > > > > > > > > > > Took a while for me to find the right device and setup the proper > > > > > system for the testing. This block missing the serial number: > > > > > > > > > > input_event(input, EV_MSC, MSC_SERIAL, 0); > > > > > > > > > > Without this line, the next tool will not get its serial number. > > > > > > > > I am tempted to simply disregard this request. It has been known for > > > > ages that the evdev values are cached, so if you do not have the value > > > > you need that means that the value has been sent previously (or you > > > > can request it upon start with an ioctl). So in this particular case, > > > > I don't really see the logic in forcing the SERIAL into the TOOL type > > > > when the tool is clearly unrelated to the serial. > > > > > > > > My fear here is that by linking together too many axes, we may enter > > > > in a state where we can not untangle them when needed. > > > > > > I see your point. We indeed added those ioctl's in the X driver to > > > avoid missing the initial states of some of the key events. > > > > > > > > > > > > > > > + input_event(input, EV_SYN, SYN_REPORT, 0); > > > > > > > + > > > > > > > + report->tool = 0; > > > > > > > +} > > > > > > > + > > > > > > > +static void hid_report_set_tool(struct hid_report *report, struct input_dev *input, > > > > > > > + unsigned int new_tool) > > > > > > > +{ > > > > > > > + if (report->tool != new_tool) > > > > > > > + hid_report_release_tool(report, input, report->tool); > > > > > > > + > > > > > > > + input_event(input, EV_KEY, new_tool, 1); > > > > > > > + report->tool = new_tool; > > > > > > > +} > > > > > > > + > > > > > > > void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value) > > > > > > > { > > > > > > > struct input_dev *input; > > > > > > > + struct hid_report *report = field->report; > > > > > > > unsigned *quirks = &hid->quirks; > > > > > > > > > > > > > > if (!usage->type) > > > > > > > @@ -1418,25 +1450,75 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct > > > > > > > } > > > > > > > > > > > > > > switch (usage->hid) { > > > > > > > + case HID_DG_ERASER: > > > > > > > + report->tool_active |= !!value; > > > > > > > + > > > > > > > + /* > > > > > > > + * if eraser is set, we must enforce BTN_TOOL_RUBBER > > > > > > > + * to accommodate for devices not following the spec. > > > > > > > + */ > > > > > > > + if (value) > > > > > > > + hid_report_set_tool(report, input, BTN_TOOL_RUBBER); > > > > > > > + else if (report->tool != BTN_TOOL_RUBBER) > > > > > > > + /* value is off, tool is not rubber, ignore */ > > > > > > > + return; > > > > > > > + > > > > > > > + /* let hid-input set BTN_TOUCH */ > > > > > > > + break; > > > > > > > + > > > > > > > case HID_DG_INVERT: > > > > > > > - *quirks = value ? (*quirks | HID_QUIRK_INVERT) : (*quirks & ~HID_QUIRK_INVERT); > > > > > > > + report->tool_active |= !!value; > > > > > > > + > > > > > > > + /* > > > > > > > + * If invert is set, we store BTN_TOOL_RUBBER. > > > > > > > + */ > > > > > > > + if (value) > > > > > > > + hid_report_set_tool(report, input, BTN_TOOL_RUBBER); > > > > > > > + else if (!report->tool_active) > > > > > > > + /* tool_active not set means Invert and Eraser are not set */ > > > > > > > + hid_report_release_tool(report, input, BTN_TOOL_RUBBER); > > > > > > > + > > > > > > > + /* no further processing */ > > > > > > > return; > > > > > > > > > > > > > > case HID_DG_INRANGE: > > > > > > > - if (value) { > > > > > > > - input_event(input, usage->type, (*quirks & HID_QUIRK_INVERT) ? BTN_TOOL_RUBBER : usage->code, 1); > > > > > > > - return; > > > > > > > + report->tool_active |= !!value; > > > > > > > + > > > > > > > + if (report->tool_active) { > > > > > > > + /* > > > > > > > + * if tool is not set but is marked as active, > > > > > > > + * assume ours > > > > > > > + */ > > > > > > > + if (!report->tool) > > > > > > > + hid_report_set_tool(report, input, usage->code); > > > > > > > + } else { > > > > > > > + hid_report_release_tool(report, input, usage->code); > > > > > > > } > > > > > > > - input_event(input, usage->type, usage->code, 0); > > > > > > > - input_event(input, usage->type, BTN_TOOL_RUBBER, 0); > > > > > > > + > > > > > > > + /* reset tool_active for the next event */ > > > > > > > + report->tool_active = false; > > > > > > > + > > > > > > > + /* no further processing */ > > > > > > > return; > > > > > > > > > > > > > > + case HID_DG_TIPSWITCH: > > > > > > > + report->tool_active |= !!value; > > > > > > > + > > > > > > > + /* if tool is set to RUBBER we should ignore the current value */ > > > > > > > + if (report->tool == BTN_TOOL_RUBBER) > > > > > > > + return; > > > > > > > > > > This case should return before HID_DG_INVERT is checked since we may > > > > > get TIPSWITCH bit before INVERT. In fact, the device that I tested > > > > > sends the tipswatch bit before the invert bit. So, I alway get a PEN > > > > > in and out before I get ERASER events, when I bring the pen in with > > > > > the side-switch/invert bit pressed. > > > > > > > > > > However, we know not all devices support INVERT. We probably have to > > > > > keep the invert quirk to decide if BTN_TOOL_PEN should be set here or > > > > > wait until HID_DG_INVERT is reached. > > > > > > > > I am under the impression that you completely missed the point of the > > > > patch series. This series re-orders the processing of the events, and > > > > if you look at the very first hunk in this patch, you'll see that the > > > > new processing ensures we treat INVERT and ERASER before TIPSWITCH, no > > > > matter the order of the device. > > > > > > Yeah, I read that part of the code, more than once. But, my evtest > > > gave me an extra set of TOOL_PEN events before TOOL_ERASER. I was > > > confused too. Then I thought maybe the code still relies on the actual > > > order of the usages. Anyway, we've done enough discussion and testing, > > > let's move on. The patchset is: > > > > > > Reviewed-by: Ping Cheng <ping.cheng@xxxxxxxxx> > > > Tested-by: Ping Cheng <ping.cheng@xxxxxxxxx> > > > > Thanks for the review. > > > > However, if the device is not working as expected, can you send me > > the hid-recorder[0] output off list so I can diagnose what is > > happening? > > Thanks for sending me the records (privately). > > And a quick look at it and it explained that spurious BTN_TOOL change. > If you look at the recordings where you take the stylus in proximity > with the eraser button pressed, you'll see: > > # ReportID: 20 / Tip Switch: 0 | Barrel Switch: 0 | Eraser: 0 | > Invert: 0 | Secondary Barrel Switch: 0 | In Range: 1 | # | X: 18699 | > Y: 11537 | Tip Pressure: 0 | 0xff00005b: -32661 | Transducer > Serial Number: 509392226 | Undefined: 1 | Battery Strength: 255 > | X Tilt: 23 | Y Tilt: 0 > E: 000000.000000 18 14 20 0b 49 11 2d 00 00 6b 80 62 b5 5c 1e 01 ff 17 00 > # ReportID: 20 / Tip Switch: 0 | Barrel Switch: 0 | Eraser: 0 | > Invert: 0 | Secondary Barrel Switch: 0 | In Range: 0 | # | X: 18699 | > Y: 11537 | Tip Pressure: 0 | 0xff00005b: -32661 | Transducer > Serial Number: 509392226 | Undefined: 1 | Battery Strength: 0 > | X Tilt: 23 | Y Tilt: 0 > E: 000000.001988 18 14 00 0b 49 11 2d 00 00 6b 80 62 b5 5c 1e 01 00 17 00 > # ReportID: 20 / Tip Switch: 0 | Barrel Switch: 0 | Eraser: 0 | > Invert: 1 | Secondary Barrel Switch: 0 | In Range: 1 | # | X: 18696 | > Y: 11543 | Tip Pressure: 0 | 0xff00005b: -32661 | Transducer > Serial Number: 509392226 | Undefined: 1 | Battery Strength: 0 > | X Tilt: 23 | Y Tilt: 0 > E: 000000.003002 18 14 28 08 49 17 2d 00 00 6b 80 62 b5 5c 1e 01 00 17 00 > > So the firmware first emits a tip event (Eraser: 0 | Invert: 0 | In > Range: 1), then realizes there is an invert incoming so it sends an > out of prox (Eraser: 0 | Invert: 0 | In Range: 0) and then the eraser > in (Eraser: 0 | Invert: 1 | In Range: 1). > > So: > - your pen is actually following the spec from Microsoft, i.e., it > doesn't switch from in-range without erasing to in-range with erasing > without going through out-of-prox, which means it is probably well > supported in the Windows world > - your firmware is not fast enough to detect the invert bit and papers > over it (but honestly, who cares that this quick event comes in). > > There is not much we can do, so I consider this "failure" to be > expected and the code is behaving properly. Well done, Benjamin! The patchset is ready. Whoever is responsible for merging it, please do so. Cheers, Ping > > [0] clone https://gitlab.freedesktop.org/libevdev/hid-tools, then pip > > install ., then `sudo hid-recorder` > > > > > > > > Thank you for your effort, Benjamin! > > > Ping > > > > > > > So when we process TIPSWITCH here, we are sure that if BTN_TOOL_RUBBER > > > > is set, either INVERT or ERASER is set to 1, whether or not they come > > > > before or after in the report. > > > > > > > > > > > > > > If you are interested in the evtest output, please let me know. I'll > > > > > share it with you offline so we don't abuse this list... > > > > > > > > evtest is the output of the kernel, and it doesn't give me much more > > > > than "it's broken". However, if you can give me the hid-recorder > > > > outputs, I'll be able to reproduce locally and compare the output as I > > > > fix the code. Of course the best would be to add test cases in the > > > > hid-tools repo, but I'll need the hid-recorder anyway to understand > > > > what is failing and to be able to write the tests. > > > > > > > > Cheers, > > > > Benjamin > > > > > > > > > > > > > > Cheers, > > > > > Ping > > > > > > > > > > > > + break; > > > > > > > + > > > > > > > case HID_DG_TIPPRESSURE: > > > > > > > if (*quirks & HID_QUIRK_NOTOUCH) { > > > > > > > int a = field->logical_minimum; > > > > > > > int b = field->logical_maximum; > > > > > > > > > > > > > > - input_event(input, EV_KEY, BTN_TOUCH, value > a + ((b - a) >> 3)); > > > > > > > + if (value > a + ((b - a) >> 3)) { > > > > > > > + input_event(input, EV_KEY, BTN_TOUCH, 1); > > > > > > > + report->tool_active = true; > > > > > > > + } > > > > > > > } > > > > > > > break; > > > > > > > > > > > > > > diff --git a/include/linux/hid.h b/include/linux/hid.h > > > > > > > index eaad0655b05c..feb8df61168f 100644 > > > > > > > --- a/include/linux/hid.h > > > > > > > +++ b/include/linux/hid.h > > > > > > > @@ -347,7 +347,7 @@ struct hid_item { > > > > > > > */ > > > > > > > #define MAX_USBHID_BOOT_QUIRKS 4 > > > > > > > > > > > > > > -#define HID_QUIRK_INVERT BIT(0) > > > > > > > +/* BIT(0) reserved for backward compatibility, was HID_QUIRK_INVERT */ > > > > > > > #define HID_QUIRK_NOTOUCH BIT(1) > > > > > > > #define HID_QUIRK_IGNORE BIT(2) > > > > > > > #define HID_QUIRK_NOGET BIT(3) > > > > > > > @@ -515,6 +515,10 @@ struct hid_report { > > > > > > > unsigned maxfield; /* maximum valid field index */ > > > > > > > unsigned size; /* size of the report (bits) */ > > > > > > > struct hid_device *device; /* associated device */ > > > > > > > + > > > > > > > + /* tool related state */ > > > > > > > + bool tool_active; /* whether the current tool is active */ > > > > > > > + unsigned int tool; /* BTN_TOOL_* */ > > > > > > > }; > > > > > > > > > > > > > > #define HID_MAX_IDS 256 > > > > > > > -- > > > > > > > 2.33.1 > > > > > > > > > > > > > > > > > > > >
