missing output reports in HID report descriptors for FFB

[foriequal0]

Current HID descriptors work fine unless you use PROTON_ENABLE_HIDRAW.
Maybe SDL in Proton could communicate with the driver through input event to provide FFB? (https://github.com/ValveSoftware/Proton/blob/1d1d7c091405c7faeeaf39c55aebb4edc4eee174/docs/CONTROLLERS.md?plain=1#L73)

However, I had to use PROTON_ENABLE_HIDRAW for some games (e.g., Assetto Corsa Rally)
With some patches (#187) I was able to make it recognized in the game, but FFB is missing.

I think it needs output reports for FFB in HID report descriptors.

[Kimplul]

I think it needs output reports for FFB in HID report descriptors.

I had a look at the HID haptics page, and I'm not sure how that would work. If you look at https://github.com/Kimplul/hid-tmff2/blob/master/docs/FFBEFFECTS.md, you'll see that fields are interpreted differently depending on the type of the packet, which I don't think the HID spec allows. So the wheel uses a vendor-defined output endpoint for FFB, but the actual data that is transferred to the endpoint is not in a format that can be defined in a sensible way with HID (hence the vendor page, I guess).

The haptics defined by the HID spec seems also fairly limited, whereas the effects supported by the wheel are more DirectX-adjacent.

[Kimplul]

Oh, forgot to mention, I opened up a PR to remove Thrustmaster wheels from using HIDRAW in SDL a while back, might be relevant here: libsdl-org/SDL#12173

[foriequal0]

maybe we could intercept the request and translate it to the vendor-defined packet format?

[Kimplul]

Does SDL handle any effects other than rumble through HIDRAW? I had a look at the code and I don't really see anything. Rumble is better than nothing I suppose, but you'd be missing pretty much all the 'real' FFB effects, and I imagine games wouldn't be too much fun to play. I would imagine a better approach would be to fix whatever bug in Proton is causing the wheel input to disappear when not using PROTON_ENABLE_HIDRAW?

[foriequal0]

I thought it would be nicer if the driver worked with the PROTON_ENABLE_HIDRAW flag and without SDL to resolve compatibility issues, like Windows, but I agree with fixing Proton and possibly SDL in general since this is the only title that I had to use PROTON_ENABLE_HIDRAW.

I suspect SDL is capable of more than rumble when HIDRAW is disabled with Usage Page 0x0F (Physical Input Device Page)?. (and does nothing when HIDRAW is enabled?)

In this comment (ValveSoftware/Proton#9220 (comment)), they tried to fix FFB by merging the HIDRAW descriptor and SDL's descriptor.

I can see some similar array of usage IDs appear with the descriptor from Windows.
(like Usage Page (PID Page), and following 0x97, 0x98, 0x99, ... and 0x26, 0x27, 0x31, '0x32', ... )

Here's the HID report descriptor dump on Windows (used https://nondebug.github.io/webhid-explorer)

productName: B66E
vendorId:    0x044F (1103) ThrustMaster, Inc.
productId:   0xB66E (46702)
opened:      true
collections[0]
  Usage: 0001:0004 (Generic Desktop > Joystick)
  Input reports: 0x02, 0x07, 0x14
  Output reports: 0x0A, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x40, 0x42, 0x43, 0x51, 0x52, 0x58, 0x59, 0x5F, 0x60, 0x82
  Feature reports: 0x0B, 0x15, 0x16, 0x50, 0xEF, 0xF0
Input report 0x02
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: FF00:0002 (Vendor-defined page 0xFF00 usage 0x0002)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Input report 0x07
  16 bits (bits 0 to 15)
    Data,Var,Abs
    Usage: 0001:0030 (Generic Desktop > X)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 65535
  16 bits (bits 16 to 31)
    Data,Var,Abs
    Usage: 0001:0031 (Generic Desktop > Y)
    Logical bounds: 0 to 1023
    Physical bounds: 0 to 1023
  16 bits (bits 32 to 47)
    Data,Var,Abs
    Usage: 0001:0035 (Generic Desktop > Rz)
    Logical bounds: 0 to 1023
    Physical bounds: 0 to 1023
  16 bits (bits 48 to 63)
    Data,Var,Abs
    Usage: 0001:0036 (Generic Desktop > Slider)
    Logical bounds: 0 to 1023
    Physical bounds: 0 to 1023
  16 bits (bits 64 to 79)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
  13 values * 1 bit (bits 80 to 92)
    Data,Var,Abs
    Usages: 0009:0001 (Button Button 1) to 0009:000D (Button Button 13)
    Logical bounds: 0 to 0
  11 bits (bits 93 to 103)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
  4 bits (bits 104 to 107)
    Data,Var,Abs,Null
    Usage: 0001:0039 (Generic Desktop > Hat Switch)
    Logical bounds: 0 to 7
    Physical bounds: 0 to 315
    Units: deg
  396 bits (bits 108 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Input report 0x14
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: FF00:0014 (Vendor-defined page 0xFF00 usage 0x0014)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Output report 0x0A
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: FF00:000A (Vendor-defined page 0xFF00 usage 0x000A)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Output report 0x14
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  8 bits (bits 8 to 15)
    Data,Ary,Abs
    Usages:
      000F:0041 (Physical Input > ET Damper)
      000F:0040 (Physical Input > ET Spring)
      000F:0034 (Physical Input > ET Sawtooth Down)
      000F:0033 (Physical Input > ET Sawtooth Up)
      000F:0031 (Physical Input > ET Sine)
      000F:0032 (Physical Input > ET Triangle)
      000F:0030 (Physical Input > ET Square)
      000F:0026 (Physical Input > ET Constant Force)
    Logical bounds: 8 to 0
  4 bits (bits 16 to 19)
    Data,Var,Abs
    Usage: 000F:002C (Physical Input usage 0x002C)
    Logical bounds: 0 to 15
    Physical bounds: 0 to 15
  1 bit (bit 20)
    Data,Var,Abs
    Usage: 000F:0029 (Physical Input usage 0x0029)
    Logical bounds: 0 to 0
  1 bit (bit 21)
    Data,Var,Abs
    Usage: 000F:0056 (Physical Input > Direction Enable)
    Logical bounds: 0 to 0
  1 bit (bit 22)
    Data,Var,Abs
    Usage: 0001:0030 (Generic Desktop > X)
    Logical bounds: 0 to 0
  1 bit (bit 23)
    Data,Var,Abs
    Usage: 0001:0031 (Generic Desktop > Y)
    Logical bounds: 0 to 0
  16 bits (bits 24 to 39)
    Data,Var,Abs
    Usage: 000F:0050 (Physical Input > Duration)
    Logical bounds: 0 to 65534
    Physical bounds: 0 to 65534
    Units: 10^-3*s
  16 bits (bits 40 to 55)
    Data,Var,Abs
    Usage: 000F:0057 (Physical Input > Direction)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 360
    Units: deg
  16 bits (bits 56 to 71)
    Data,Var,Abs
    Usage: 000F:00A7 (Physical Input > Start Delay)
    Logical bounds: 0 to 65534
    Physical bounds: 0 to 65534
    Units: 10^-3*s
  7 bits (bits 72 to 78)
    Data,Var,Abs
    Usage: 000F:0053 (Physical Input > Trigger Button)
    Logical bounds: 0 to 127
    Physical bounds: 0 to 127
  1 bit (bit 79)
    Data,Var,Abs
    Usage: 000F:002A (Physical Input usage 0x002A)
    Logical bounds: 0 to 0
  16 bits (bits 80 to 95)
    Data,Var,Abs
    Usage: 000F:0054 (Physical Input > Trigger Repeat Interval)
    Logical bounds: 0 to 65534
    Physical bounds: 0 to 65534
    Units: 10^-3*s
  408 bits (bits 96 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x15
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  16 bits (bits 8 to 23)
    Data,Var,Abs
    Usage: 000F:005C (Physical Input > Attack Time)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 65535
    Units: 10^-3*s
  16 bits (bits 24 to 39)
    Data,Var,Abs
    Usage: 000F:005B (Physical Input > Attack Level)
    Logical bounds: 0 to 32767
    Physical bounds: 0 to 10000
  16 bits (bits 40 to 55)
    Data,Var,Abs
    Usage: 000F:005E (Physical Input > Fade Time)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 65535
    Units: 10^-3*s
  16 bits (bits 56 to 71)
    Data,Var,Abs
    Usage: 000F:005D (Physical Input > Fade Level)
    Logical bounds: 0 to 32767
    Physical bounds: 0 to 10000
  432 bits (bits 72 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x16
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  16 bits (bits 8 to 23)
    Data,Var,Abs
    Usage: 000F:0070 (Physical Input > Magnitude)
    Logical bounds: -32767 to 32767
    Physical bounds: -10000 to 10000
  480 bits (bits 24 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x17
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  16 bits (bits 8 to 23)
    Data,Var,Abs
    Usage: 000F:0070 (Physical Input > Magnitude)
    Logical bounds: 0 to 32767
    Physical bounds: 0 to 10000
  16 bits (bits 24 to 39)
    Data,Var,Abs
    Usage: 000F:006F (Physical Input > Offset)
    Logical bounds: -32767 to 32767
    Physical bounds: -10000 to 10000
  16 bits (bits 40 to 55)
    Data,Var,Abs
    Usage: 000F:0071 (Physical Input > Phase)
    Logical bounds: 0 to 32767
    Physical bounds: 0 to 360
  16 bits (bits 56 to 71)
    Data,Var,Abs
    Usage: 000F:0072 (Physical Input > Period)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 65535
    Units: 10^-3*s
  16 bits (bits 72 to 87)
    Data,Var,Abs
    Usage: 000F:002B (Physical Input usage 0x002B)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 65535
  416 bits (bits 88 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x18
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  8 bits (bits 8 to 15)
    Data,Var,Abs
    Usage: 000F:0023 (Physical Input > Parameter Block Offset)
    Logical bounds: 0 to 1
  16 bits (bits 16 to 31)
    Data,Var,Abs
    Usage: 000F:0061 (Physical Input > Positive Coefficient)
    Logical bounds: -32767 to 32767
    Physical bounds: -10000 to 10000
  16 bits (bits 32 to 47)
    Data,Var,Abs
    Usage: 000F:0062 (Physical Input > Negative Coefficient)
    Logical bounds: -32767 to 32767
    Physical bounds: -10000 to 10000
  16 bits (bits 48 to 63)
    Data,Var,Abs
    Usage: 000F:0060 (Physical Input > CP Offset)
    Logical bounds: -32767 to 32767
    Physical bounds: -10000 to 10000
  16 bits (bits 64 to 79)
    Data,Var,Abs
    Usage: 000F:0065 (Physical Input > Dead Band)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 10000
  16 bits (bits 80 to 95)
    Data,Var,Abs
    Usage: 000F:0063 (Physical Input > Positive Saturation)
    Logical bounds: 0 to 32767
    Physical bounds: 0 to 10000
  16 bits (bits 96 to 111)
    Data,Var,Abs
    Usage: 000F:0064 (Physical Input > Negative Saturation)
    Logical bounds: 0 to 32767
    Physical bounds: 0 to 10000
  392 bits (bits 112 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x19
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: 00FF:030B (Unknown usage page 0x00FF usage 0x030B)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Output report 0x40
  8 bits (bits 0 to 7)
    Data,Ary,Abs
    Usages: 00FF:0311 (Unknown usage page 0x00FF usage 0x0311) to 00FF:0321 (Unknown usage page 0x00FF usage 0x0321)
    Logical bounds: 17 to 0
  16 bits (bits 8 to 23)
    Data,Var,Abs
    Usage: 00FF:0303 (Unknown usage page 0x00FF usage 0x0303)
    Logical bounds: 0 to 65535
    Physical bounds: 0 to 10000
  480 bits (bits 24 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x42
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: 00FF:0309 (Unknown usage page 0x00FF usage 0x0309)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Output report 0x43
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:007E (Physical Input > Device Gain)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 10000
  496 bits (bits 8 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x51
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  8 bits (bits 8 to 15)
    Data,Ary,Abs
    Usages:
      000F:007A (Physical Input > Op Effect Start Solo)
      000F:0079 (Physical Input > Op Effect Start)
      000F:007B (Physical Input > Op Effect Stop)
    Logical bounds: 3 to 0
  8 bits (bits 16 to 23)
    Data,Var,Abs
    Usage: 000F:007C (Physical Input > Loop Count)
    Logical bounds: 0 to 254
  480 bits (bits 24 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x52
  8 bits (bits 0 to 7)
    Data,Ary,Abs
    Usages:
      000F:009C (Physical Input > DC Device Continue)
      000F:009B (Physical Input > DC Device Pause)
      000F:0098 (Physical Input > DC Disable Actuators)
      000F:0097 (Physical Input > DC Enable Actuators)
      000F:0099 (Physical Input > DC Stop All Effects)
      000F:009A (Physical Input > DC Device Reset)
    Logical bounds: 6 to 0
  496 bits (bits 8 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x58
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  496 bits (bits 8 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Output report 0x59
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: 00FF:030C (Unknown usage page 0x00FF usage 0x030C)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Output report 0x5F
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: 00FF:0305 (Unknown usage page 0x00FF usage 0x0305)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Output report 0x60
  63 values * 8 bits (bits 0 to 503)
    Data,Var,Abs
    Usage: 00FF:0307 (Unknown usage page 0x00FF usage 0x0307)
    Logical bounds: 0 to 255
    Physical bounds: 0 to 255
Output report 0x82
  16 bits (bits 0 to 15)
    Data,Var,Abs
    Usage: 0001:0030 (Generic Desktop > X)
    Logical bounds: -32767 to 32767
    Physical bounds: -10000 to 10000
  16 bits (bits 16 to 31)
    Data,Var,Abs
    Usage: 0001:0031 (Generic Desktop > Y)
    Logical bounds: -32767 to 32767
    Physical bounds: -10000 to 10000
  472 bits (bits 32 to 503)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Feature report 0x0B
  15 bits (bits 0 to 14)
    Cnst,Var,Abs
    Usage: 000F:0080 (Physical Input > RAM Pool Size)
    Logical bounds: 0 to 32767
  1 bit (bit 15)
    Cnst,Var,Abs
    Usage: 000F:00A9 (Physical Input > Device Managed Pool)
    Logical bounds: 0 to 0
  8 bits (bits 16 to 23)
    Cnst,Var,Abs
    Usage: 000F:0083 (Physical Input > Simultaneous Effects Max)
    Logical bounds: 0 to 255
  160 bits (bits 24 to 183)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Feature report 0x15
  8 bits (bits 0 to 7)
    Data,Ary,Abs
    Usages:
      000F:0041 (Physical Input > ET Damper)
      000F:0040 (Physical Input > ET Spring)
      000F:0034 (Physical Input > ET Sawtooth Down)
      000F:0033 (Physical Input > ET Sawtooth Up)
      000F:0031 (Physical Input > ET Sine)
      000F:0032 (Physical Input > ET Triangle)
      000F:0030 (Physical Input > ET Square)
      000F:0026 (Physical Input > ET Constant Force)
    Logical bounds: 8 to 0
  176 bits (bits 8 to 183)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Feature report 0x16
  8 bits (bits 0 to 7)
    Data,Ary,Abs
    Usages:
      000F:008E (Physical Input > Block Load Error)
      000F:008D (Physical Input > Block Load Full)
      000F:008C (Physical Input > Block Load Success)
    Logical bounds: 3 to 0
  8 bits (bits 8 to 15)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  168 bits (bits 16 to 183)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Feature report 0x50
  8 bits (bits 0 to 7)
    Data,Var,Abs
    Usage: 000F:0022 (Physical Input > Effect Block Index)
    Logical bounds: 0 to 255
  176 bits (bits 8 to 183)
    Cnst,Ary,Abs
    Logical bounds: 0 to 0
Feature report 0xEF
  23 values * 8 bits (bits 0 to 183)
    Data,Ary,Abs
    Usages: 000A:0001 (Ordinal Instance 1) to 000A:0017 (Ordinal Instance 23)
    Logical bounds: 255 to 0
Feature report 0xF0
  23 values * 8 bits (bits 0 to 183)
    Data,Ary,Abs
    Usages: 000A:0001 (Ordinal Instance 1) to 000A:0017 (Ordinal Instance 23)
    Logical bounds: 255 to 0

Anyway, I'm not completely understanding what I'm saying 😅, I'm just dumping some information I gathered.

[Kimplul]

In this comment (ValveSoftware/Proton#9220 (comment)), they tried to fix FFB by merging the HIDRAW descriptor and SDL's descriptor.

Maybe I'm reading this wrong or missing some context, but the next comment says the patch worked when disabling PROTON_ENABLE_HIDRAW?

Anycase, thanks for the Windows descriptor, really interesting. I definitely don't remember seeing anything like that last time I messed around with the wheel on Windows (which admittedly was years ago by now, heh), so I'm assuming this is new-ish. Looks like the new descriptor is creating a separate output report for each effect type, which is different from the 'old' way of sending all effect updates as proprietary packets to 0x60 (which is present in the reports, I guess for backwards compatibility? Neat!)

I'll have to check on my own wheel if this is something that a firmware update provides. If it is, then I can likely raise the minimum supported FW version and skip the rdesc modification altogether, which would be fantastic. Worst case I guess would be that it's dependent on hardware iteration, with newer wheels having a different hard-coded descriptor than old ones, and semi-bad would be the Windows driver modifying the rdesc on the fly, either case meaning we can't trust the rdesc that the wheel provides when connected and some kind of kludge is necessary.

[foriequal0]

Maybe I'm reading this wrong or missing some context, but the next comment says the patch worked when disabling PROTON_ENABLE_HIDRAW?

You're reading it right. I'm the one who is having a hard time understanding 😅.

Wine generates an HID descriptor: https://github.com/ValveSoftware/wine/blob/eb63de9c3c08bb222dd439e1cea3be4217d3d0f9/dlls/winebus.sys/bus_sdl.c#L351
Then it presents to the game.
I guess the game doesn't handle Wine's input report descriptor properly, but Wine's output report descriptor well in that case.
So, they decided to present the HIDRAW input report descriptor to the game, and translate the Wine input report (which was already translated from the HIDRAW input report or input event) to the HIDRAW input report format on the fly.
(Wheel -> HIDRAW -> Wine -> Wine HID -> bus_event_queue_input_report -> HIDRAW -> Game ?).

Meanwhile, Wine's output report descriptor has no problem, so they kept that part untouched, and handled by Wine.

https://github.com/berarma/new-lg4ff/blob/2092db19f7b40854e0427a1b2e39eda9f8d0c3cd/hid-lg.c#L428
lg4ff doesn't have descriptor, and I've heard that PROTON_ENABLE_HIDRAW fixes the input registration problem but loss of FFB.

I felt the multiple rounds of HIDRAW -> Wine HID -> HIDRAW conversions are more error-prone, and it's harder to recompile the wine than recompile hid-tmff2 😅.

edit: some confusing mention about SDL, and wrong guess about signed/unsigned.

[foriequal0]

I changed the axis report size of Wine's generated HID report to 16 bits from 32 bits, and the inputs are registered properly, and FFB works fine.
ValveSoftware/Proton#9220 (comment)

I think this issue is between Wine and the the game at this point.
Thank you for your help.