* Patch "hwmon: (max1111) Return -ENODEV from max1111_read_channel if not instantiated" has been added to the 4.4-stable tree
@ 2016-04-12 21:00 gregkh
0 siblings, 0 replies; only message in thread
From: gregkh @ 2016-04-12 21:00 UTC (permalink / raw
To: linux, arnd, gregkh; +Cc: stable, stable-commits
This is a note to let you know that I've just added the patch titled
hwmon: (max1111) Return -ENODEV from max1111_read_channel if not instantiated
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hwmon-max1111-return-enodev-from-max1111_read_channel-if-not-instantiated.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From 3c2e2266a5bd2d1cef258e6e54dca1d99946379f Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Sat, 26 Mar 2016 12:28:05 -0700
Subject: hwmon: (max1111) Return -ENODEV from max1111_read_channel if not instantiated
From: Guenter Roeck <linux@roeck-us.net>
commit 3c2e2266a5bd2d1cef258e6e54dca1d99946379f upstream.
arm:pxa_defconfig can result in the following crash if the max1111 driver
is not instantiated.
Unhandled fault: page domain fault (0x01b) at 0x00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: : 1b [#1] PREEMPT ARM
Modules linked in:
CPU: 0 PID: 300 Comm: kworker/0:1 Not tainted 4.5.0-01301-g1701f680407c #10
Hardware name: SHARP Akita
Workqueue: events sharpsl_charge_toggle
task: c390a000 ti: c391e000 task.ti: c391e000
PC is at max1111_read_channel+0x20/0x30
LR is at sharpsl_pm_pxa_read_max1111+0x2c/0x3c
pc : [<c03aaab0>] lr : [<c0024b50>] psr: 20000013
...
[<c03aaab0>] (max1111_read_channel) from [<c0024b50>]
(sharpsl_pm_pxa_read_max1111+0x2c/0x3c)
[<c0024b50>] (sharpsl_pm_pxa_read_max1111) from [<c00262e0>]
(spitzpm_read_devdata+0x5c/0xc4)
[<c00262e0>] (spitzpm_read_devdata) from [<c0024094>]
(sharpsl_check_battery_temp+0x78/0x110)
[<c0024094>] (sharpsl_check_battery_temp) from [<c0024f9c>]
(sharpsl_charge_toggle+0x48/0x110)
[<c0024f9c>] (sharpsl_charge_toggle) from [<c004429c>]
(process_one_work+0x14c/0x48c)
[<c004429c>] (process_one_work) from [<c0044618>] (worker_thread+0x3c/0x5d4)
[<c0044618>] (worker_thread) from [<c004a238>] (kthread+0xd0/0xec)
[<c004a238>] (kthread) from [<c000a670>] (ret_from_fork+0x14/0x24)
This can occur because the SPI controller driver (SPI_PXA2XX) is built as
module and thus not necessarily loaded. While building SPI_PXA2XX into the
kernel would make the problem disappear, it appears prudent to ensure that
the driver is instantiated before accessing its data structures.
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/hwmon/max1111.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/hwmon/max1111.c
+++ b/drivers/hwmon/max1111.c
@@ -85,6 +85,9 @@ static struct max1111_data *the_max1111;
int max1111_read_channel(int channel)
{
+ if (!the_max1111 || !the_max1111->spi)
+ return -ENODEV;
+
return max1111_read(&the_max1111->spi->dev, channel);
}
EXPORT_SYMBOL(max1111_read_channel);
@@ -258,6 +261,9 @@ static int max1111_remove(struct spi_dev
{
struct max1111_data *data = spi_get_drvdata(spi);
+#ifdef CONFIG_SHARPSL_PM
+ the_max1111 = NULL;
+#endif
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&spi->dev.kobj, &max1110_attr_group);
sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
Patches currently in stable-queue which might be from linux@roeck-us.net are
queue-4.4/hwmon-max1111-return-enodev-from-max1111_read_channel-if-not-instantiated.patch
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2016-04-12 21:00 Patch "hwmon: (max1111) Return -ENODEV from max1111_read_channel if not instantiated" has been added to the 4.4-stable tree gregkh
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