linux-kernel - [PATCH 07/12] hdaps: delay calibration to first hardware query

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 06 Aug 2006 10:26:52 +0300
From:	Shem Multinymous <multinymous@...il.com>
To:	Robert Love <rlove@...ve.org>
Cc:	Jean Delvare <khali@...ux-fr.org>,
	Greg Kroah-Hartman <gregkh@...e.de>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	linux-kernel@...r.kernel.org, hdaps-devel@...ts.sourceforge.net
Subject: [PATCH 07/12] hdaps: delay calibration to first hardware query

The hdaps driver currently calibrates its rest position upon
initialization, which can take several seconds on first module load
(and delays the boot process accordingly). This patch delays 
calibration to the first successful hardware query, when the
information is available anyway. Writes to the "calibrate" sysfs
attribute are handled likewise.

Signed-off-by: Shem Multinymous <multinymous@...il.com>
---
 hdaps.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff -up a/drivers/hwmon/hdaps.c a/drivers/hwmon/hdaps.c
--- a/drivers/hwmon/hdaps.c
+++ a/drivers/hwmon/hdaps.c
@@ -66,6 +66,7 @@ static struct timer_list hdaps_timer;
 static struct platform_device *pdev;
 static struct input_dev *hdaps_idev;
 static unsigned int hdaps_invert;
+static int needs_calibration = 0;
 
 /* Latest state readout: */
 static int pos_x, pos_y;      /* position */
@@ -125,6 +126,11 @@ static int __hdaps_update(int fast)
 	temperature = data.val[EC_ACCEL_IDX_TEMP1];
 
 	stale_readout = 0;
+	if (needs_calibration) {
+		rest_x = pos_x;
+		rest_y = pos_y;
+		needs_calibration = 0;
+	}
 
 	return 0;
 }
@@ -270,9 +276,9 @@ static struct platform_driver hdaps_driv
  */
 static void hdaps_calibrate(void)
 {
+	needs_calibration = 1;
 	hdaps_update();
-	rest_x = pos_x;
-	rest_y = pos_y;
+	/* If that fails, the mousedev poll will take care of things later. */
 }
 
 /* Timer handler for updating the input device. Runs in softirq context,
@@ -502,8 +508,8 @@ static int __init hdaps_init(void)
 		goto out_group;
 	}
 
-	/* initial calibrate for the input device */
-	hdaps_calibrate();
+	/* calibration for the input device (deferred to avoid delay) */
+	needs_calibration = 1;
 
 	/* initialize the input class */
 	hdaps_idev->name = "hdaps";
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/