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 Slaby <jslaby@suse.cz>
Tue, 11 Apr 2017 06:04:37 +0000 (08:04 +0200)
commitfc0a62426de73859c1892ab2e61857d5bc283d2f
tree61c7d6657814c560ecc69872cbb55dbff1c94206
parent03bc30d2744acb2aec65bdd8abe8e471ebd0c9e6
HID: i2c-hid: Add sleep between POWER ON and RESET

commit a89af4abdf9b353cdd6f61afc0eaaac403304873 upstream.

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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
drivers/hid/i2c-hid/i2c-hid.c