diff options
author | Alan Stern <stern@rowland.harvard.edu> | 2014-03-18 10:39:05 -0400 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-19 14:00:32 -0700 |
commit | 1d10255c1c496557a5674e651c4ebbe0f61279f2 (patch) | |
tree | 7d65e464bc4ba39240f124111c8c4d30dd7e76e8 /drivers/usb/core/otg_whitelist.h | |
parent | 6aec044cc2f5670cf3b143c151c8be846499bd15 (diff) |
USB: disable reset-resume when USB_QUIRK_RESET is set
The USB_QUIRK_RESET flag indicates that a USB device changes its
identity in some way when it is reset. It may lose its firmware, its
descriptors may change, or it may switch back to a default mode of
operation.
If a device does this, the kernel needs to avoid resetting it. Resets
are likely to fail, or worse, succeed while changing the device's
state in a way the system can't detect.
This means we should disable the reset-resume mechanism whenever this
quirk flag is present. An attempted reset-resume will fail, the
device will be logically disconnected, and later on the hub driver
will rediscover and re-enumerate the device. This will cause the
appropriate udev events to be generated, so that userspace will have a
chance to switch the device into its normal operating mode, if
necessary.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Oliver Neukum <oliver@neukum.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core/otg_whitelist.h')
0 files changed, 0 insertions, 0 deletions