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| author | Hans de Goede <hdegoede@redhat.com> | 2019-04-20 13:22:10 +0200 |
|---|---|---|
| committer | Benjamin Tissoires <benjamin.tissoires@redhat.com> | 2019-04-23 18:02:46 +0200 |
| commit | 096377525cdb8251e4656085efc988bdf733fb4c (patch) | |
| tree | 92a71548b73a50894bcac63d1d1b39903122c2bf /drivers/hid | |
| parent | e54abaf675ca76e026a104790e3aaa2b47ee7497 (diff) | |
| download | linux-096377525cdb8251e4656085efc988bdf733fb4c.tar.bz2 | |
HID: logitech-hidpp: use RAP instead of FAP to get the protocol version
According to the logitech_hidpp_2.0_specification_draft_2012-06-04.pdf doc:
https://lekensteyn.nl/files/logitech/logitech_hidpp_2.0_specification_draft_2012-06-04.pdf
We should use a register-access-protocol request using the short input /
output report ids. This is necessary because 27MHz HID++ receivers have
a max-packetsize on their HIP++ endpoint of 8, so they cannot support
long reports. Using a feature-access-protocol request (which is always
long or very-long) with these will cause a timeout error, followed by
the hidpp driver treating the device as not being HID++ capable.
This commit fixes this by switching to using a rap request to get the
protocol version.
Besides being tested with a (046d:c517) 27MHz receiver with various
27MHz keyboards and mice, this has also been tested to not cause
regressions on a non-unifying dual-HID++ nano receiver (046d:c534) with
k270 and m185 HID++-2.0 devices connected and on a unifying/dj receiver
(046d:c52b) with a HID++-2.0 Logitech Rechargeable Touchpad T650.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/hid-logitech-hidpp.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index b0da186ef5e7..243426097c51 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -837,13 +837,16 @@ static int hidpp_root_get_feature(struct hidpp_device *hidpp, u16 feature, static int hidpp_root_get_protocol_version(struct hidpp_device *hidpp) { + const u8 ping_byte = 0x5a; + u8 ping_data[3] = { 0, 0, ping_byte }; struct hidpp_report response; int ret; - ret = hidpp_send_fap_command_sync(hidpp, + ret = hidpp_send_rap_command_sync(hidpp, + REPORT_ID_HIDPP_SHORT, HIDPP_PAGE_ROOT_IDX, CMD_ROOT_GET_PROTOCOL_VERSION, - NULL, 0, &response); + ping_data, sizeof(ping_data), &response); if (ret == HIDPP_ERROR_INVALID_SUBID) { hidpp->protocol_major = 1; @@ -863,8 +866,14 @@ static int hidpp_root_get_protocol_version(struct hidpp_device *hidpp) if (ret) return ret; - hidpp->protocol_major = response.fap.params[0]; - hidpp->protocol_minor = response.fap.params[1]; + if (response.rap.params[2] != ping_byte) { + hid_err(hidpp->hid_dev, "%s: ping mismatch 0x%02x != 0x%02x\n", + __func__, response.rap.params[2], ping_byte); + return -EPROTO; + } + + hidpp->protocol_major = response.rap.params[0]; + hidpp->protocol_minor = response.rap.params[1]; print_version: hid_info(hidpp->hid_dev, "HID++ %u.%u device connected.\n", |