Check read_fifo pointer before using it since we can't assume it is always set adding new sensors. This patch fixes the following crash: irq 277: nobody cared (try booting with the "irqpoll" option) CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc5-00322-g792b824-dirty #7 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [<c0112750>] (unwind_backtrace) from [<c010d018>] (show_stack+0x10/0x14) [<c010d018>] (show_stack) from [<c0c2bfc8>] (dump_stack+0xd8/0x10c) [<c0c2bfc8>] (dump_stack) from [<c01923fc>] (__report_bad_irq+0x24/0xc0) [<c01923fc>] (__report_bad_irq) from [<c0192820>] (note_interrupt+0x27c/0x2dc) [<c0192820>] (note_interrupt) from [<c018f174>] (handle_irq_event_percpu+0x54/0x7c) [<c018f174>] (handle_irq_event_percpu) from [<c018f1d4>] (handle_irq_event+0x38/0x5c) [<c018f1d4>] (handle_irq_event) from [<c0193664>] (handle_level_irq+0xc8/0x154) [<c0193664>] (handle_level_irq) from [<c018df58>] (generic_handle_irq+0x20/0x34) [<c018df58>] (generic_handle_irq) from [<c053c348>] (mxc_gpio_irq_handler+0xc4/0xf8) [<c053c348>] (mxc_gpio_irq_handler) from [<c053c3e0>] (mx3_gpio_irq_handler+0x64/0xb8) [<c053c3e0>] (mx3_gpio_irq_handler) from [<c018df58>] (generic_handle_irq+0x20/0x34) [<c018df58>] (generic_handle_irq) from [<c018e550>] (__handle_domain_irq+0x64/0xe0) [<c018e550>] (__handle_domain_irq) from [<c0529610>] (gic_handle_irq+0x4c/0xa0) [<c0529610>] (gic_handle_irq) from [<c0101a70>] (__irq_svc+0x70/0x98) Exception stack(0xc1301f10 to 0xc1301f58 1f00: 00000001 00000006 00000000 c130c340 1f20: c1300000 c1308928 00000001 c1308960 00000000 c12b9db0 c1308908 00000000 1f40: 00000000 c1301f60 c0182010 c0109508 20000013 ffffffff [<c0101a70>] (__irq_svc) from [<c0109508>] (arch_cpu_idle+0x20/0x3c) [<c0109508>] (arch_cpu_idle) from [<c015ed70>] (do_idle+0x1bc/0x2bc) [<c015ed70>] (do_idle) from [<c015f204>] (cpu_startup_entry+0x18/0x1c) [<c015f204>] (cpu_startup_entry) from [<c1200e68>] (start_kernel+0x440/0x504) [<c1200e68>] (start_kernel) from [<00000000>] (0x0) handlers: [<62052c0d>] st_lsm6dsx_handler_irq threaded [<f2004b92>] st_lsm6dsx_handler_thread Fixes: 52f4b1f19679 ("iio: imu: st_lsm6dsx: add support for accel/gyro unit of lsm9ds1") Tested-by: Bobby Jones <rjones@xxxxxxxxxxxxx> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> --- drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 3 +++ drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c index ef579650fd52..cabd4bfeab17 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c @@ -586,6 +586,9 @@ int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw) { int err; + if (!hw->settings->fifo_ops.read_fifo) + return -ENOTSUPP; + mutex_lock(&hw->fifo_lock); hw->settings->fifo_ops.read_fifo(hw); diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c index df270905f21d..eac695663b6f 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c @@ -1815,6 +1815,9 @@ static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private) event = st_lsm6dsx_report_motion_event(hw); + if (!hw->settings->fifo_ops.read_fifo) + return event ? IRQ_HANDLED : IRQ_NONE; + mutex_lock(&hw->fifo_lock); count = hw->settings->fifo_ops.read_fifo(hw); mutex_unlock(&hw->fifo_lock); -- 2.21.0