On Tue, Jul 25, 2023 at 10:23:41AM -0400, Hugo Villeneuve wrote: > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > > Make sure we wait at least 3us before initiating communication with > the device after reset. That says what you do, but not _why_ you do it? Please read the kernel documentation again for how to write a good changelog text. It's usually the hardest part of submitting a patch. > > Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > Reviewed-by: Lech Perczak <lech.perczak@xxxxxxxxxxxxxxx> > Tested-by: Lech Perczak <lech.perczak@xxxxxxxxxxxxxxx> > --- > drivers/tty/serial/sc16is7xx.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c > index 49213be60baf..718e982e1efe 100644 > --- a/drivers/tty/serial/sc16is7xx.c > +++ b/drivers/tty/serial/sc16is7xx.c > @@ -1526,6 +1526,12 @@ static int sc16is7xx_probe(struct device *dev, > regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT, > SC16IS7XX_IOCONTROL_SRESET_BIT); > > + /* > + * After reset, the host must wait at least 3us before initializing a > + * communication with the device. > + */ > + usleep_range(5, 10); 5, 10 is NOT 3us. :(