I believe this question has already been answered on the LKML (source)
Date Tue, 28 May 2013 12:13:45 +0200 (CEST) From Jiri Kosina <>
Subject Re: [PATCH 0/2] Holtek gaming mouse driver, and the necessity
for it instead of increasing HID_MAX_USAGES
On Tue, 21 May 2013, Christian Ohm wrote:
Is there any reason why HID_MAX_USAGES shouldn't be more than 12288?
Well, the reasoning is a mixture of current implementation, and
reasonability.
we currently have statically allocated arrays on a per-parser basis, for parsing usages and collection indices. If the number of max
usages is going to grow in an uncontrolled manner, we'll have to
change the way our parser works (which is not impossible, of
course).
most of the ocurences of huge max usages being presented by the devices have actually turned out to be bogus and could have been
fixed by patching the report descriptor in order to reflect the
real behavior of the device
Thanks,
-- Jiri Kosina SUSE Labs