Messages in this thread | | | Date | Fri, 26 Nov 2021 13:37:55 +0100 | From | Maarten Brock <> | Subject | Re: [PATCH] USB: serial: cp210x: fix CP2105 GPIO registration |
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On 2021-11-26 10:43, Johan Hovold wrote: > When generalising GPIO support and adding support for CP2102N, the GPIO > registration for some CP2105 devices accidentally broke. Specifically, > when all the pins of a port are in "modem" mode, and thus unavailable > for GPIO use, the GPIO chip would now be registered without having > initialised the number of GPIO lines. This would in turn be rejected by > gpiolib and some errors messages would be printed (but importantly > probe > would still succeed). > > Fix this by initialising the number of GPIO lines before registering > the > GPIO chip. > > Note that as for the other device types, and as when all CP2105 pins > are > muxed for LED function, the GPIO chip is registered also when no pins > are available for GPIO use. > > Reported-by: Maarten Brock <m.brock@vanmierlo.com> > Link: > https://lore.kernel.org/r/5eb560c81d2ea1a2b4602a92d9f48a89@vanmierlo.com > Fixes: c8acfe0aadbe ("USB: serial: cp210x: implement GPIO support for > CP2102N") > Cc: stable@vger.kernel.org # 4.19 > Cc: Karoly Pados <pados@pados.hu> > Signed-off-by: Johan Hovold <johan@kernel.org> > --- > drivers/usb/serial/cp210x.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c > index 7705328034ca..8a60c0d56863 100644 > --- a/drivers/usb/serial/cp210x.c > +++ b/drivers/usb/serial/cp210x.c > @@ -1635,6 +1635,8 @@ static int cp2105_gpioconf_init(struct usb_serial > *serial) > > /* 2 banks of GPIO - One for the pins taken from each serial port */ > if (intf_num == 0) { > + priv->gc.ngpio = 2; > + > if (mode.eci == CP210X_PIN_MODE_MODEM) { > /* mark all GPIOs of this interface as reserved */ > priv->gpio_altfunc = 0xff; > @@ -1645,8 +1647,9 @@ static int cp2105_gpioconf_init(struct usb_serial > *serial) > priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) & > CP210X_ECI_GPIO_MODE_MASK) >> > CP210X_ECI_GPIO_MODE_OFFSET); > - priv->gc.ngpio = 2; > } else if (intf_num == 1) { > + priv->gc.ngpio = 3; > + > if (mode.sci == CP210X_PIN_MODE_MODEM) { > /* mark all GPIOs of this interface as reserved */ > priv->gpio_altfunc = 0xff; > @@ -1657,7 +1660,6 @@ static int cp2105_gpioconf_init(struct usb_serial > *serial) > priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) & > CP210X_SCI_GPIO_MODE_MASK) >> > CP210X_SCI_GPIO_MODE_OFFSET); > - priv->gc.ngpio = 3; > } else { > return -ENODEV; > }
Tested-by: Maarten Brock <m.brock@vanmierlo.com>
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