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authorStefan Agner <stefan@agner.ch>2018-01-11 14:47:40 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-11 18:39:52 +0100
commitb8626f1dc29d3eee444bfaa92146ec7b291ef41c (patch)
treeeda57d029c3e6a09fb82ec2fab884cf9b564a331
parentceb176118103479a171da941aecc457767b535c7 (diff)
downloadop-kernel-dev-b8626f1dc29d3eee444bfaa92146ec7b291ef41c.zip
op-kernel-dev-b8626f1dc29d3eee444bfaa92146ec7b291ef41c.tar.gz
usb: misc: usb3503: make sure reset is low for at least 100us
When using a GPIO which is high by default, and initialize the driver in USB Hub mode, initialization fails with: [ 111.757794] usb3503 0-0008: SP_ILOCK failed (-5) The reason seems to be that the chip is not properly reset. Probe does initialize reset low, however some lines later the code already set it back high, which is not long enouth. Make sure reset is asserted for at least 100us by inserting a delay after initializing the reset pin during probe. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/misc/usb3503.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/misc/usb3503.c b/drivers/usb/misc/usb3503.c
index 465dbf6..f723f7b 100644
--- a/drivers/usb/misc/usb3503.c
+++ b/drivers/usb/misc/usb3503.c
@@ -279,6 +279,8 @@ static int usb3503_probe(struct usb3503 *hub)
if (gpio_is_valid(hub->gpio_reset)) {
err = devm_gpio_request_one(dev, hub->gpio_reset,
GPIOF_OUT_INIT_LOW, "usb3503 reset");
+ /* Datasheet defines a hardware reset to be at least 100us */
+ usleep_range(100, 10000);
if (err) {
dev_err(dev,
"unable to request GPIO %d as reset pin (%d)\n",
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