| From 264904ccc33c604d4b3141bbd33808152dfac45b Mon Sep 17 00:00:00 2001 |
| From: Oliver Neukum <oneukum@suse.com> |
| Date: Wed, 10 Feb 2016 11:33:18 +0100 |
| Subject: usb: retry reset if a device times out |
| |
| From: Oliver Neukum <oneukum@suse.com> |
| |
| 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(-) |
| |
| --- a/drivers/usb/core/hub.c |
| +++ b/drivers/usb/core/hub.c |
| @@ -4426,7 +4426,13 @@ hub_port_init(struct usb_hub *hub, struc |
| 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 = |
