From 3a22b872e923954853cabd5a18f41da1846bccdb Mon Sep 17 00:00:00 2001 From: Lan Tianyu Date: Wed, 5 Sep 2012 13:44:37 +0800 Subject: [PATCH] usb: Fail a get config when the port is powered off. Alan Stern pointed out that a USB port could potentially get powered off when the attached USB device is in the middle of enumerating, due to race conditions: http://marc.info/?l=linux-usb&m=134130616707548&w=2 If that happens, we need to ensure the enumeration fails. If a call to usb_get_descriptor() fails for a reason other than a Stall, return an error. That should handle the case where the port is powered off. Acked-by: Alan Stern Signed-off-by: Lan Tianyu Signed-off-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index f4bdd0ce8d5..7199adccf44 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -702,6 +702,8 @@ int usb_get_configuration(struct usb_device *dev) if (result < 0) { dev_err(ddev, "unable to read config index %d " "descriptor/%s: %d\n", cfgno, "start", result); + if (result != -EPIPE) + goto err; dev_err(ddev, "chopping to %d config(s)\n", cfgno); dev->descriptor.bNumConfigurations = cfgno; break; -- 2.20.1