Stall on bcm2708_i2c_master_xfer #1762
Description
Today I noticed that my Raspberry was stuck for 4 hours, from 04:59 to 08:47, than it recovered. From logs it looks like it's some race in i2c. I'm using WiringPi to interact with multiple DS2482-800 and MCP23017 chips. The application is interacting with the chips from multiple threads and is running 24 hours.
The application was running fine from Oct 27 2016 till today, since October I've updated kernel version few times.
Kernel 4.4.26-v7+
[<805b6274>] (__schedule) from [<805b67ec>] (schedule+0x50/0xa8)
[<805b67ec>] (schedule) from [<805b964c>] (schedule_timeout+0x14c/0x270)
[<805b964c>] (schedule_timeout) from [<805b732c>] (wait_for_common+0xbc/0x17c)
[<805b732c>] (wait_for_common) from [<805b742c>] (wait_for_completion_timeout+0x1c/0x20)
[<805b742c>] (wait_for_completion_timeout) from [<7f0ac57c>] (bcm2708_i2c_master_xfer+0x114/0x27c [i2c_bcm2708])
[<7f0ac57c>] (bcm2708_i2c_master_xfer [i2c_bcm2708]) from [<8045ac04>] (__i2c_transfer+0x144/0x50c)
[<8045ac04>] (__i2c_transfer) from [<8045b040>] (i2c_transfer+0x74/0xa0)
[<8045b040>] (i2c_transfer) from [<8045b5c0>] (i2c_smbus_xfer+0x498/0x8ec)
[<8045b5c0>] (i2c_smbus_xfer) from [<7f08f468>] (i2cdev_ioctl_smbus+0x160/0x23c [i2c_dev])
[<7f08f468>] (i2cdev_ioctl_smbus [i2c_dev]) from [<7f08f924>] (i2cdev_ioctl+0xc0/0x270 [i2c_dev])
[<7f08f924>] (i2cdev_ioctl [i2c_dev]) from [<80169b30>] (do_vfs_ioctl+0x424/0x614)
[<80169b30>] (do_vfs_ioctl) from [<80169d64>] (SyS_ioctl+0x44/0x6c)
[<80169d64>] (SyS_ioctl) from [<8000fb40>] (ret_fast_syscall+0x0/0x1c)