This is a note to let you know that I've just added the patch titled
usb: misc: usb3503: make sure reset is low for at least 100us
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: usb-misc-usb3503-make-sure-reset-is-low-for-at-least-100us.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From b8626f1dc29d3eee444bfaa92146ec7b291ef41c Mon Sep 17 00:00:00 2001
From: Stefan Agner stefan@agner.ch Date: Thu, 11 Jan 2018 14:47:40 +0100 Subject: usb: misc: usb3503: make sure reset is low for at least 100us
From: Stefan Agner stefan@agner.ch
commit b8626f1dc29d3eee444bfaa92146ec7b291ef41c upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/misc/usb3503.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/usb/misc/usb3503.c +++ b/drivers/usb/misc/usb3503.c @@ -292,6 +292,8 @@ static int usb3503_probe(struct usb3503 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",
Patches currently in stable-queue which might be from stefan@agner.ch are
queue-4.9/usb-misc-usb3503-make-sure-reset-is-low-for-at-least-100us.patch