The datasheet for the ksz9893 and ksz9477 switches recommend waiting at least 100us after the de-assertion of reset before trying to program the device through any interface.
Also switch the existing msleep() call to usleep_range() as recommended in Documentation/timers/timers-howto.rst. The 2ms range used here is somewhat arbitrary, as long as the reset is asserted for at least 10ms we should be ok. Signed-off-by: Paul Barker <pbar...@konsulko.com> Reviewed-by: Florian Fainelli <f.faine...@gmail.com> --- drivers/net/dsa/microchip/ksz_common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 8d53b12d40a8..a31738662d95 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -400,8 +400,9 @@ int ksz_switch_register(struct ksz_device *dev, if (dev->reset_gpio) { gpiod_set_value_cansleep(dev->reset_gpio, 1); - mdelay(10); + usleep_range(10000, 12000); gpiod_set_value_cansleep(dev->reset_gpio, 0); + usleep_range(100, 1000); } mutex_init(&dev->dev_mutex); -- 2.28.0