Patchwork [v4,21/32] usb: hid: change serial number to "42".

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Submitter Gerd Hoffmann
Date Jan. 12, 2011, 11:20 a.m.
Message ID <>
Download mbox | patch
Permalink /patch/78548/
State New
Headers show


Gerd Hoffmann - Jan. 12, 2011, 11:20 a.m.
It would be nice to have some way to signal our hid devices support
remote wakeup.  There is a descriptor bit for that of course.  Problem
with using is one is that older qemu versions used to set the bit even
though they did *not* support remote wakeup.  Bummer.

This patch changes the serial number of our hid devices from "1" to "42"
to signal "it is safe to enable remote wakeup".  The serial number was
choosen because it isn't used for anything and it is available in sysfs
so it is easy to match it using udev rules like this:

ACTION=="add", SUBSYSTEM=="usb", \
	ATTR{product}=="QEMU USB Tablet", ATTR{serial}=="42", \
	RUN+="usb_enable_autosuspend %p"

Signed-off-by: Gerd Hoffmann <>
 hw/usb-hid.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)


diff --git a/hw/usb-hid.c b/hw/usb-hid.c
index 60fa57f..1fec163 100644
--- a/hw/usb-hid.c
+++ b/hw/usb-hid.c
@@ -90,7 +90,7 @@  static const USBDescStrings desc_strings = {
     [STR_PRODUCT_MOUSE]    = "QEMU USB Mouse",
     [STR_PRODUCT_TABLET]   = "QEMU USB Tablet",
-    [STR_SERIALNUMBER]     = "1",
+    [STR_SERIALNUMBER]     = "42", /* == remote wakeup works */
     [STR_CONFIG_MOUSE]     = "HID Mouse",
     [STR_CONFIG_TABLET]    = "HID Tablet",
     [STR_CONFIG_KEYBOARD]  = "HID Keyboard",