On Tue, Dec 10, 2024 at 10:36 PM Sasha Levin <sashal@xxxxxxxxxx> wrote: > > This is a note to let you know that I've just added the patch titled > > HID: bpf: Fix NKRO on Mistel MD770 > > to the 5.15-stable tree which can be found at: > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary > > The filename of the patch is: > hid-bpf-fix-nkro-on-mistel-md770.patch > and it can be found in the queue-5.15 subdirectory. > > If you, or anyone else, feels it should not be added to the stable tree, > please let <stable@xxxxxxxxxxxxxxx> know about it. Please drop this patch (and in all previous releases). Again, it makes no sense to backport any files in drivers/hid/bpf/progs on kernels before 6.11, and even then, it makes very little value as they are also tracked in a different userspace project (udev-hid-bpf). FWIW, HID-BPF was introduced in v6.3, so it's even more surprisingly surprising to see such a patch added here. Cheers, Benjamin > > > > commit cd9ab7edb94431f02c68383c089dc12fbbe00475 > Author: Benjamin Tissoires <bentiss@xxxxxxxxxx> > Date: Thu Oct 17 18:34:58 2024 +0200 > > HID: bpf: Fix NKRO on Mistel MD770 > > [ Upstream commit 9bc089307e8dff7797233308372b4a90ce8f79be ] > > Mistel MD770 keyboard (using Holtek Semiconductor, Inc. controller) has > a quirk in report descriptor in one of its interfaces (more detail in > the source file). Fix up the descriptor to allow NKRO to work again. > > Tested by loading the BPF program and confirming that 8 simultaneous > keypresses work. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=218495 > Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/122 > Signed-off-by: Tatsuyuki Ishi <ishitatsuyuki@xxxxxxxxx> > Acked-by: Jiri Kosina <jkosina@xxxxxxxx> > Link: https://patch.msgid.link/20241017-import_bpf_6-13-v2-1-6a7acb89a97f@xxxxxxxxxx > Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > diff --git a/drivers/hid/bpf/progs/Mistel__MD770.bpf.c b/drivers/hid/bpf/progs/Mistel__MD770.bpf.c > new file mode 100644 > index 0000000000000..fb8b5a6968b12 > --- /dev/null > +++ b/drivers/hid/bpf/progs/Mistel__MD770.bpf.c > @@ -0,0 +1,154 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2024 Tatsuyuki Ishi > + */ > + > +#include "vmlinux.h" > +#include "hid_bpf.h" > +#include "hid_bpf_helpers.h" > +#include <bpf/bpf_tracing.h> > + > +#define VID_HOLTEK 0x04D9 > +#define PID_MD770 0x0339 > +#define RDESC_SIZE 203 > + > +HID_BPF_CONFIG( > + HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_HOLTEK, PID_MD770) > +); > + > +/* > + * The Mistel MD770 keyboard reports the first 6 simultaneous key presses > + * through the first interface, and anything beyond that through a second > + * interface. Unfortunately, the second interface's report descriptor has an > + * error, causing events to be malformed and ignored. This HID-BPF driver > + * fixes the descriptor to allow NKRO to work again. > + * > + * For reference, this is the original report descriptor: > + * > + * 0x05, 0x01, // Usage Page (Generic Desktop) 0 > + * 0x09, 0x80, // Usage (System Control) 2 > + * 0xa1, 0x01, // Collection (Application) 4 > + * 0x85, 0x01, // Report ID (1) 6 > + * 0x19, 0x81, // Usage Minimum (129) 8 > + * 0x29, 0x83, // Usage Maximum (131) 10 > + * 0x15, 0x00, // Logical Minimum (0) 12 > + * 0x25, 0x01, // Logical Maximum (1) 14 > + * 0x95, 0x03, // Report Count (3) 16 > + * 0x75, 0x01, // Report Size (1) 18 > + * 0x81, 0x02, // Input (Data,Var,Abs) 20 > + * 0x95, 0x01, // Report Count (1) 22 > + * 0x75, 0x05, // Report Size (5) 24 > + * 0x81, 0x01, // Input (Cnst,Arr,Abs) 26 > + * 0xc0, // End Collection 28 > + * 0x05, 0x0c, // Usage Page (Consumer Devices) 29 > + * 0x09, 0x01, // Usage (Consumer Control) 31 > + * 0xa1, 0x01, // Collection (Application) 33 > + * 0x85, 0x02, // Report ID (2) 35 > + * 0x15, 0x00, // Logical Minimum (0) 37 > + * 0x25, 0x01, // Logical Maximum (1) 39 > + * 0x95, 0x12, // Report Count (18) 41 > + * 0x75, 0x01, // Report Size (1) 43 > + * 0x0a, 0x83, 0x01, // Usage (AL Consumer Control Config) 45 > + * 0x0a, 0x8a, 0x01, // Usage (AL Email Reader) 48 > + * 0x0a, 0x92, 0x01, // Usage (AL Calculator) 51 > + * 0x0a, 0x94, 0x01, // Usage (AL Local Machine Browser) 54 > + * 0x09, 0xcd, // Usage (Play/Pause) 57 > + * 0x09, 0xb7, // Usage (Stop) 59 > + * 0x09, 0xb6, // Usage (Scan Previous Track) 61 > + * 0x09, 0xb5, // Usage (Scan Next Track) 63 > + * 0x09, 0xe2, // Usage (Mute) 65 > + * 0x09, 0xea, // Usage (Volume Down) 67 > + * 0x09, 0xe9, // Usage (Volume Up) 69 > + * 0x0a, 0x21, 0x02, // Usage (AC Search) 71 > + * 0x0a, 0x23, 0x02, // Usage (AC Home) 74 > + * 0x0a, 0x24, 0x02, // Usage (AC Back) 77 > + * 0x0a, 0x25, 0x02, // Usage (AC Forward) 80 > + * 0x0a, 0x26, 0x02, // Usage (AC Stop) 83 > + * 0x0a, 0x27, 0x02, // Usage (AC Refresh) 86 > + * 0x0a, 0x2a, 0x02, // Usage (AC Bookmarks) 89 > + * 0x81, 0x02, // Input (Data,Var,Abs) 92 > + * 0x95, 0x01, // Report Count (1) 94 > + * 0x75, 0x0e, // Report Size (14) 96 > + * 0x81, 0x01, // Input (Cnst,Arr,Abs) 98 > + * 0xc0, // End Collection 100 > + * 0x05, 0x01, // Usage Page (Generic Desktop) 101 > + * 0x09, 0x02, // Usage (Mouse) 103 > + * 0xa1, 0x01, // Collection (Application) 105 > + * 0x09, 0x01, // Usage (Pointer) 107 > + * 0xa1, 0x00, // Collection (Physical) 109 > + * 0x85, 0x03, // Report ID (3) 111 > + * 0x05, 0x09, // Usage Page (Button) 113 > + * 0x19, 0x01, // Usage Minimum (1) 115 > + * 0x29, 0x08, // Usage Maximum (8) 117 > + * 0x15, 0x00, // Logical Minimum (0) 119 > + * 0x25, 0x01, // Logical Maximum (1) 121 > + * 0x75, 0x01, // Report Size (1) 123 > + * 0x95, 0x08, // Report Count (8) 125 > + * 0x81, 0x02, // Input (Data,Var,Abs) 127 > + * 0x05, 0x01, // Usage Page (Generic Desktop) 129 > + * 0x09, 0x30, // Usage (X) 131 > + * 0x09, 0x31, // Usage (Y) 133 > + * 0x16, 0x01, 0x80, // Logical Minimum (-32767) 135 > + * 0x26, 0xff, 0x7f, // Logical Maximum (32767) 138 > + * 0x75, 0x10, // Report Size (16) 141 > + * 0x95, 0x02, // Report Count (2) 143 > + * 0x81, 0x06, // Input (Data,Var,Rel) 145 > + * 0x09, 0x38, // Usage (Wheel) 147 > + * 0x15, 0x81, // Logical Minimum (-127) 149 > + * 0x25, 0x7f, // Logical Maximum (127) 151 > + * 0x75, 0x08, // Report Size (8) 153 > + * 0x95, 0x01, // Report Count (1) 155 > + * 0x81, 0x06, // Input (Data,Var,Rel) 157 > + * 0x05, 0x0c, // Usage Page (Consumer Devices) 159 > + * 0x0a, 0x38, 0x02, // Usage (AC Pan) 161 > + * 0x95, 0x01, // Report Count (1) 164 > + * 0x81, 0x06, // Input (Data,Var,Rel) 166 > + * 0xc0, // End Collection 168 > + * 0xc0, // End Collection 169 > + * 0x05, 0x01, // Usage Page (Generic Desktop) 170 > + * 0x09, 0x06, // Usage (Keyboard) 172 > + * 0xa1, 0x01, // Collection (Application) 174 > + * 0x85, 0x04, // Report ID (4) 176 > + * 0x05, 0x07, // Usage Page (Keyboard) 178 > + * 0x95, 0x01, // Report Count (1) 180 > + * 0x75, 0x08, // Report Size (8) 182 > + * 0x81, 0x03, // Input (Cnst,Var,Abs) 184 > + * 0x95, 0xe8, // Report Count (232) 186 > + * 0x75, 0x01, // Report Size (1) 188 > + * 0x15, 0x00, // Logical Minimum (0) 190 > + * 0x25, 0x01, // Logical Maximum (1) 192 > + * 0x05, 0x07, // Usage Page (Keyboard) 194 > + * 0x19, 0x00, // Usage Minimum (0) 196 > + * 0x29, 0xe7, // Usage Maximum (231) 198 > + * 0x81, 0x00, // Input (Data,Arr,Abs) 200 <- change to 0x81, 0x02 (Data,Var,Abs) > + * 0xc0, // End Collection 202 > + */ > + > +SEC(HID_BPF_RDESC_FIXUP) > +int BPF_PROG(hid_rdesc_fixup_mistel_md770, struct hid_bpf_ctx *hctx) > +{ > + __u8 *data = hid_bpf_get_data(hctx, 0, HID_MAX_DESCRIPTOR_SIZE); > + > + if (!data) > + return 0; /* EPERM check */ > + > + if (data[201] == 0x00) > + data[201] = 0x02; > + > + return 0; > +} > + > +HID_BPF_OPS(mistel_md770) = { > + .hid_rdesc_fixup = (void *)hid_rdesc_fixup_mistel_md770, > +}; > + > +SEC("syscall") > +int probe(struct hid_bpf_probe_args *ctx) > +{ > + ctx->retval = ctx->rdesc_size != RDESC_SIZE; > + if (ctx->retval) > + ctx->retval = -EINVAL; > + > + return 0; > +} > + > +char _license[] SEC("license") = "GPL"; >
