[PATCH] hid-input: Use a larger event buffer for MT devices

From: "Henrik Rydberg" <rydberg@euromail.se>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
	Stephane Chatty <chatty@enac.fr>,
	Rafi Rubin <rafi@seas.upenn.edu>,
	Michael Poole <mdpoole@troilus.org>,
	Henrik Rydberg <rydberg@euromail.se>
Subject: [PATCH] hid-input: Use a larger event buffer for MT devices
Date: Mon, 14 Jun 2010 13:49:41 +0200	[thread overview]
Message-ID: <1276516181-4519-1-git-send-email-rydberg@euromail.se> (raw)

The MT devices produce a lot of data. Tell the underlying input device
approximately how many events will be sent per synchronization, to allow
for better buffering. The number is a template based on continuously
reporting details for each finger on a single hand.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
---
Hi Jiri,

This patch goes together with the evdev buffer patchset, which Dmitry
is going to queue for 2.6.36.

Cheers,
Henrik

 drivers/hid/hid-input.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 7a0d2e4..69d152e 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -534,6 +534,9 @@ mapped:
 			input_set_abs_params(input, usage->code, a, b, (b - a) >> 8, (b - a) >> 4);
 		else	input_set_abs_params(input, usage->code, a, b, 0, 0);
 
+		/* use a larger default input buffer for MT devices */
+		if (usage->code == ABS_MT_POSITION_X && input->hint_events_per_packet == 0)
+			input_set_events_per_packet(input, 60);
 	}
 
 	if (usage->type == EV_ABS &&
-- 
1.6.3.3

