[PATCH] hwmon: (ams) Fix device removal sequence

[PATCH] hwmon: (ams) Fix device removal sequence

[Jean Delvare]

Some code that is in ams_exit() (the module exit code) should instead
be called when the device (not module) is removed. It probably doesn't
make much of a difference in the PMU case, but in the I2C case it does
matter.

I make no guarantee that my fix isn't racy, I'm not familiar enough
with the ams driver code to tell for sure.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stelian Pop <stelian@popies.net>
Cc: Michael Hanselmann <linux-kernel@hansmi.ch>
Cc: stable@kernel.org
---
Christian tested the I2C variant of the chip, it would be nice if
someone could test the PMU variant too.

 drivers/hwmon/ams/ams-core.c |   11 +++++++----
 drivers/hwmon/ams/ams-i2c.c  |    2 ++
 drivers/hwmon/ams/ams-pmu.c  |    2 ++
 drivers/hwmon/ams/ams.h      |    1 +
 4 files changed, 12 insertions(+), 4 deletions(-)

--- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams-core.c	2009-06-10 05:05:27.000000000 +0200
+++ linux-2.6.33-rc3/drivers/hwmon/ams/ams-core.c	2010-01-07 17:14:25.000000000 +0100
@@ -213,7 +213,7 @@ int __init ams_init(void)
 	return -ENODEV;
 }
 
-void ams_exit(void)
+void ams_sensor_detach(void)
 {
 	/* Remove input device */
 	ams_input_exit();
@@ -221,9 +221,6 @@ void ams_exit(void)
 	/* Remove attributes */
 	device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
 
-	/* Shut down implementation */
-	ams_info.exit();
-
 	/* Flush interrupt worker
 	 *
 	 * We do this after ams_info.exit(), because an interrupt might
@@ -239,6 +236,12 @@ void ams_exit(void)
 	pmf_unregister_irq_client(&ams_freefall_client);
 }
 
+static void __exit ams_exit(void)
+{
+	/* Shut down implementation */
+	ams_info.exit();
+}
+
 MODULE_AUTHOR("Stelian Pop, Michael Hanselmann");
 MODULE_DESCRIPTION("Apple Motion Sensor driver");
 MODULE_LICENSE("GPL");
--- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams-i2c.c	2009-06-10 05:05:27.000000000 +0200
+++ linux-2.6.33-rc3/drivers/hwmon/ams/ams-i2c.c	2010-01-07 17:12:46.000000000 +0100
@@ -238,6 +238,8 @@ static int ams_i2c_probe(struct i2c_clie
 static int ams_i2c_remove(struct i2c_client *client)
 {
 	if (ams_info.has_device) {
+		ams_sensor_detach();
+
 		/* Disable interrupts */
 		ams_i2c_set_irq(AMS_IRQ_ALL, 0);
 
--- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams-pmu.c	2009-06-10 05:05:27.000000000 +0200
+++ linux-2.6.33-rc3/drivers/hwmon/ams/ams-pmu.c	2010-01-07 17:13:47.000000000 +0100
@@ -133,6 +133,8 @@ static void ams_pmu_get_xyz(s8 *x, s8 *y
 
 static void ams_pmu_exit(void)
 {
+	ams_sensor_detach();
+
 	/* Disable interrupts */
 	ams_pmu_set_irq(AMS_IRQ_ALL, 0);
 
--- linux-2.6.33-rc3.orig/drivers/hwmon/ams/ams.h	2009-06-10 05:05:27.000000000 +0200
+++ linux-2.6.33-rc3/drivers/hwmon/ams/ams.h	2010-01-07 17:11:43.000000000 +0100
@@ -61,6 +61,7 @@ extern struct ams ams_info;
 
 extern void ams_sensors(s8 *x, s8 *y, s8 *z);
 extern int ams_sensor_attach(void);
+extern void ams_sensor_detach(void);
 
 extern int ams_pmu_init(struct device_node *np);
 extern int ams_i2c_init(struct device_node *np);


-- 
Jean Delvare

Re: [PATCH] hwmon: (ams) Fix device removal sequence

[Christian Kujau]

Ben,

I cannot find those two patches from Jean [0] in your tree, I take it 
they'll be included and pushed to Linus in 2.6.34 then?

(Although I had hoped to see them in 2.6.33, I'm "testing"[1] them since 
 -rc2 on my PowerBook)

Thanks,
Christian.

[0] http://lists.ozlabs.org/pipermail/linuxppc-dev/2010-February/079958.html
    http://lists.ozlabs.org/pipermail/linuxppc-dev/2010-February/079959.html
[1] http://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg40983.html

-- 
BOFH excuse #342:

HTTPD Error 4004 : very old Intel cpu - insufficient processing power