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| author | Guenter Roeck <linux@roeck-us.net> | 2016-03-26 20:28:05 +0100 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2016-03-27 19:37:48 +0200 |
| commit | 3c2e2266a5bd2d1cef258e6e54dca1d99946379f (patch) | |
| tree | b5fea39f361072ec8e6c99fc4ba447a02e9124ed /drivers/hwmon/max1111.c | |
| parent | Linux 4.6-rc1 (diff) | |
| download | linux-3c2e2266a5bd2d1cef258e6e54dca1d99946379f.tar.xz linux-3c2e2266a5bd2d1cef258e6e54dca1d99946379f.zip | |
hwmon: (max1111) Return -ENODEV from max1111_read_channel if not instantiated
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>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/max1111.c')
| -rw-r--r-- | drivers/hwmon/max1111.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/hwmon/max1111.c b/drivers/hwmon/max1111.c index 36544c4f653c..303d0c9df907 100644 --- 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_device *spi) { 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); |