@@ -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);
@@ -260,6 +263,9 @@ 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);
This is a note to let you know that I have just added a patch titled hwmon: (max1111) Return -ENODEV from max1111_read_channel if not instantiated to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt39. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From aed0a8d99b7bdcc84986402bfeb6d2a5306c4747 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 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: Kamal Mostafa <kamal@canonical.com> --- drivers/hwmon/max1111.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.7.4