HID: i2c-hid: Add sleep between POWER ON and RESET
authorBrendan McGrath <redmcg@redmandi.dyndns.org>
Fri, 6 Jan 2017 21:01:38 +0000 (08:01 +1100)
committerJiri Kosina <jkosina@suse.cz>
Wed, 11 Jan 2017 20:55:35 +0000 (21:55 +0100)
commita89af4abdf9b353cdd6f61afc0eaaac403304873
tree340ac23fe4ee8d576a9be12146b94234f31cc2a7
parent1ebb71143758f45dc0fa76e2f48429e13b16d110
HID: i2c-hid: Add sleep between POWER ON and RESET

Support for the Asus Touchpad was recently added. It turns out this
device can fail initialisation (and become unusable) when the RESET
command is sent too soon after the POWER ON command.

Unfortunately the i2c-hid specification does not specify the need for
a delay between these two commands. But it was discovered the Windows
driver has a 1ms delay.

As a result, this patch modifies the i2c-hid module to add a sleep
inbetween the POWER ON and RESET commands which lasts between 1ms and 5ms.

See https://github.com/vlasenko/hid-asus-dkms/issues/24 for further
details.

Signed-off-by: Brendan McGrath <redmcg@redmandi.dyndns.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/hid/i2c-hid/i2c-hid.c