Devices which may take a while to initialize during probe and which have no strong reason to probe synchronously can request asynchronous probing as default probe strategy. This can speed-up start times on some platforms. The KX022A gets probe delayed for at least two reasons. It enables the supply regulator, (which is likely to have ramp-up delay if it was disabled) and additionally it delays while the sensor itself is initializing. Changing to asynchronous probing may cause problems. Some of which are discussed in: https://lore.kernel.org/all/06db017f-e985-4434-8d1d-02ca2100cca0@xxxxxxxxxxxxx/ Enable asynchronous probing for KX022A. Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx> --- I am unsure if this change is 100% safe - but I don't immediately see the harm. Please let me know if some of you have more experience on problems when using asynchronous probing with IIO devices. --- drivers/iio/accel/kionix-kx022a-i2c.c | 1 + drivers/iio/accel/kionix-kx022a-spi.c | 1 + 2 files changed, 2 insertions(+) diff --git a/drivers/iio/accel/kionix-kx022a-i2c.c b/drivers/iio/accel/kionix-kx022a-i2c.c index e6fd02d931b6..ee982206e5dd 100644 --- a/drivers/iio/accel/kionix-kx022a-i2c.c +++ b/drivers/iio/accel/kionix-kx022a-i2c.c @@ -40,6 +40,7 @@ static struct i2c_driver kx022a_i2c_driver = { .driver = { .name = "kx022a-i2c", .of_match_table = kx022a_of_match, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, .probe_new = kx022a_i2c_probe, }; diff --git a/drivers/iio/accel/kionix-kx022a-spi.c b/drivers/iio/accel/kionix-kx022a-spi.c index 9cd047f7b346..f45a46899a5f 100644 --- a/drivers/iio/accel/kionix-kx022a-spi.c +++ b/drivers/iio/accel/kionix-kx022a-spi.c @@ -46,6 +46,7 @@ static struct spi_driver kx022a_spi_driver = { .driver = { .name = "kx022a-spi", .of_match_table = kx022a_of_match, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, .probe = kx022a_spi_probe, .id_table = kx022a_id, -- 2.40.0 -- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =]
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