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| author | Lan Tianyu <tianyu.lan@intel.com> | 2012-09-05 13:44:37 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-09-10 13:04:01 -0700 |
| commit | 3a22b872e923954853cabd5a18f41da1846bccdb (patch) | |
| tree | 8b528be0d99bb136c9eb2b21d97c151440c701f4 /drivers/usb/core | |
| parent | f7ac7787ad361e31a7972e2854ed8dc2eedfac3b (diff) | |
| download | op-kernel-dev-3a22b872e923954853cabd5a18f41da1846bccdb.zip op-kernel-dev-3a22b872e923954853cabd5a18f41da1846bccdb.tar.gz | |
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 <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/config.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index f4bdd0c..7199adc 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; |
