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authorJohan Hovold <johan@kernel.org>2021-11-26 10:43:48 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-12-22 09:29:39 +0100
commitd2bb4378e2bb9ea80dfba89cfc8ee8bdd3dfcd3e (patch)
tree1080d93ed3f4ccb9de7804be63b74a5f3261283f
parentbae7f0808202b20aad4a7aa15ae455fac6520520 (diff)
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USB: serial: cp210x: fix CP2105 GPIO registration
commit 83b67041f3eaf33f98a075249aa7f4c7617c2f85 upstream. 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> Link: https://lore.kernel.org/r/20211126094348.31698-1-johan@kernel.org Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Maarten Brock <m.brock@vanmierlo.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/serial/cp210x.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 004b6598706b..50f289b124d0 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -1552,6 +1552,8 @@ 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;
@@ -1562,8 +1564,9 @@ 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;
@@ -1574,7 +1577,6 @@ 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;
}