summaryrefslogtreecommitdiff
path: root/tools/lib/python
diff options
context:
space:
mode:
authorBenedek Kupper <kupper.benedek@gmail.com>2025-10-07 22:35:44 +0200
committerJiri Kosina <jkosina@suse.com>2025-11-26 17:21:48 +0100
commitd6f4941f1b4f3e701e422dfbfee024264294f91f (patch)
treeb0426b10ee1fdd55996134090a0987a158e99714 /tools/lib/python
parentbaa120439ac0c803a9962df838eeda28846bc93a (diff)
drivers: hid: renegotiate resolution multipliers with device after reset
The scroll resolution multipliers are set in the context of hidinput_connect(), which is only called at probe time: when the host changes the value on the device with a SET_REPORT(FEATURE), and the device accepts it, these multipliers are stored on the host side, and used to calculate the final scroll event values sent to userspace. After a USB suspend, the resume operation on many hubs and chipsets involve a USB reset signal as well. A reset on the device side clears all previous state information, including the value of the multiplier report. This reset is not handled by the multiplier handling logic, so what ends up happening is the host is still expecting high-resolution scroll events, but the device is reset to default resolution, making the effective, user-perceived scroll speed incredibly slow. The solution is to renegotiate the multiplier selection after each reset. This is not the only bug related to the high-resolution scrolling implementation in the kernel (the other one is https://bugzilla.kernel.org/show_bug.cgi?id=220144), but for this one, there is no device side workaround for, leading to poor user experience with our product: https://github.com/UltimateHackingKeyboard/firmware/issues/1155 https://github.com/UltimateHackingKeyboard/firmware/issues/1261 https://github.com/UltimateHackingKeyboard/firmware/pull/1355 This patch was tested by an affected user and has been reported to fix the issue (see discussion in 1355). Signed-off-by: Benedek Kupper <kupper.benedek@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.com>
Diffstat (limited to 'tools/lib/python')
0 files changed, 0 insertions, 0 deletions