Linux Input/HID development
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From: Oliver <oliverburns.kernel@gmail.com>
To: dmitry.torokhov@gmail.com
Cc: kees@kernel.org, linux-input@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Oliver <oliverburns.kernel@gmail.com>
Subject: [PATCH] Input: sur40: fix MAX_CONTACTS value based on PixelSense specification
Date: Mon, 15 Jun 2026 00:08:47 +0100	[thread overview]
Message-ID: <20260614230847.4938-1-oliverburns.kernel@gmail.com> (raw)

The Samsung SUR40 with Microsoft PixelSense is offically specified to
support 52 simultaneuous touch contacts, not 64. The value of 64 was an
unverified guess as noted by the FIXME comment. Update MAX_CONTACTS to
match the documented hardware specification and remove the FIXME.

Signed-off-by: Oliver <oliverburns.kernel@gmail.com>
---
 drivers/input/touchscreen/sur40.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c
index fe63d53d56db..77ec2c94b91f 100644
--- a/drivers/input/touchscreen/sur40.c
+++ b/drivers/input/touchscreen/sur40.c
@@ -128,8 +128,8 @@ struct sur40_image_header {
 /* polling interval (ms) */
 #define POLL_INTERVAL 1
 
-/* maximum number of contacts FIXME: this is a guess? */
-#define MAX_CONTACTS 64
+/* maximum number of contacts */
+#define MAX_CONTACTS 52
 
 /* control commands */
 #define SUR40_GET_VERSION 0xb0 /* 12 bytes string    */
-- 
2.54.0


             reply	other threads:[~2026-06-14 23:14 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-14 23:08 Oliver [this message]
2026-06-14 23:26 ` [PATCH] Input: sur40: fix MAX_CONTACTS value based on PixelSense specification sashiko-bot

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