From 951822beba268f76af9463c69095284df20311f6 Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneukum@suse.com> Date: Wed, 10 Feb 2016 11:33:18 +0100 Subject: [PATCH] usb: retry reset if a device times out commit 264904ccc33c604d4b3141bbd33808152dfac45b upstream. Some devices I got show an inability to operate right after power on if they are already connected. They are beyond recovery if the descriptors are requested multiple times. So in case of a timeout we rather bail early and reset again. But it must be done only on the first loop lest we get into a reset/time out spiral that can be overcome with a retry. This patch is a rework of a patch that fell through the cracks. http://www.spinics.net/lists/linux-usb/msg103263.html Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/usb/core/hub.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 1560f3f3e756..a44db86018c7 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4426,7 +4426,13 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, r = -EPROTO; break; } - if (r == 0) + /* + * Some devices time out if they are powered on + * when already connected. They need a second + * reset. But only on the first attempt, + * lest we get into a time out/reset loop + */ + if (r == 0 || (r == -ETIMEDOUT && j == 0)) break; } udev->descriptor.bMaxPacketSize0 = -- 2.30.9