Commit 3f9bce7a authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Jonathan Cameron

iio: imu: st_lsm6dsx: fix edge-trigger interrupts

If we are using edge IRQs, new samples can arrive while processing
current interrupt since there are no hw guarantees the irq line
stays "low" long enough to properly detect the new interrupt.
In this case the new sample will be missed.
Polling FIFO status register in st_lsm6dsx_handler_thread routine
allow us to read new samples even if the interrupt arrives while
processing previous data and the timeslot where the line is "low"
is too short to be properly detected.

Fixes: 89ca88a7 ("iio: imu: st_lsm6dsx: support active-low interrupts")
Fixes: 290a6ce1 ("iio: imu: add support to lsm6dsx driver")
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/5e93cda7dc1e665f5685c53ad8e9ea71dbae782d.1605378871.git.lorenzo@kernel.org
Cc: <Stable@vger.kernel.org>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 3418bd7c
...@@ -2069,19 +2069,35 @@ st_lsm6dsx_report_motion_event(struct st_lsm6dsx_hw *hw) ...@@ -2069,19 +2069,35 @@ st_lsm6dsx_report_motion_event(struct st_lsm6dsx_hw *hw)
static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private) static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private)
{ {
struct st_lsm6dsx_hw *hw = private; struct st_lsm6dsx_hw *hw = private;
int fifo_len = 0, len;
bool event; bool event;
int count;
event = st_lsm6dsx_report_motion_event(hw); event = st_lsm6dsx_report_motion_event(hw);
if (!hw->settings->fifo_ops.read_fifo) if (!hw->settings->fifo_ops.read_fifo)
return event ? IRQ_HANDLED : IRQ_NONE; return event ? IRQ_HANDLED : IRQ_NONE;
/*
* If we are using edge IRQs, new samples can arrive while
* processing current interrupt since there are no hw
* guarantees the irq line stays "low" long enough to properly
* detect the new interrupt. In this case the new sample will
* be missed.
* Polling FIFO status register allow us to read new
* samples even if the interrupt arrives while processing
* previous data and the timeslot where the line is "low" is
* too short to be properly detected.
*/
do {
mutex_lock(&hw->fifo_lock); mutex_lock(&hw->fifo_lock);
count = hw->settings->fifo_ops.read_fifo(hw); len = hw->settings->fifo_ops.read_fifo(hw);
mutex_unlock(&hw->fifo_lock); mutex_unlock(&hw->fifo_lock);
return count || event ? IRQ_HANDLED : IRQ_NONE; if (len > 0)
fifo_len += len;
} while (len > 0);
return fifo_len || event ? IRQ_HANDLED : IRQ_NONE;
} }
static int st_lsm6dsx_irq_setup(struct st_lsm6dsx_hw *hw) static int st_lsm6dsx_irq_setup(struct st_lsm6dsx_hw *hw)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment