Pavlik,
Here is a small patch relative to 2.6.4-rc2 that does three things:
- In hid_init_reports(), establish a idle-period of 1ms before
initiating the Get_Request() requests. It appears there are buggy
keyboards (such as the BTC keyboard) where setting the idle period
affects not just the Interrupt In pipe, but the control pipe's
Get_Requests as well. I _believe_ this should be harmless to
properly operating HID devices, but I can't know for sure.
- Enhance the "submitting ctrl urb" debug message with some additional,
useful info
- Replace hard-coded 0x0a with manifest constant "HID_REQ_SET_IDLE" to
improve radability.
Without the first change, connecting the BTC keyboard to a host caused
the HID driver to timeout after a longish period of time. Actually,
the exact behavior seemed to depend on a number of things:
- After freshly booting the machine (which is an Itanium 2 box),
loading hid.ko would cause a timeout on interface 0 (keyboard) and
would function fine on interface 1 (power-control buttons).
- After removing and re-inserting hid.ko, the timeouts happened
on both interfaces (presumably because the previous loading
of hid.ko established an infinite idle period).
I was able to get rid of the timeout on a freshly booted machine by
switching the keyboard interface to protocol 1 before doing the
Get_Reportss, but the timeouts came back after unloading/reloading
hid.ko, so that alone doesn't seem sufficient (plus I couldn't find a
good way to determine whether an interface is a keyboard supporting
the boot protocol...).
The other two changes are only cosmetic, but I think they're useful.
One question: isn't HID supposed to switch to protocol 1 for keyboards
supporting the boot protocol? My reading of the specs is that, yes,
it should, but I couldn't find any place in the driver where this is
done.
Anyhow, if the patch looks good, please apply.
--david
===== drivers/usb/input/hid-core.c 1.72 vs edited =====
--- 1.72/drivers/usb/input/hid-core.c Wed Jan 28 23:12:59 2004
+++ edited/drivers/usb/input/hid-core.c Tue Mar 9 21:19:16 2004
@@ -1086,7 +1086,9 @@
hid->cr->wIndex = cpu_to_le16(hid->ifnum);
hid->cr->wLength = cpu_to_le16(hid->urbctrl->transfer_buffer_length);
- dbg("submitting ctrl urb");
+ dbg("submitting ctrl urb: %s wValue=0x%04x wIndex=0x%04x wLength=%u",
+ hid->cr->bRequest == HID_REQ_SET_REPORT ? "Set_Report" : "Get_Report",
+ hid->cr->wValue, hid->cr->wIndex, hid->cr->wLength);
if (usb_submit_urb(hid->urbctrl, GFP_ATOMIC)) {
err("usb_submit_urb(ctrl) failed");
@@ -1265,6 +1267,23 @@
int len;
int err, ret;
+ /*
+ * The Set_Idle request is supposed to affect only the
+ * "Interrupt In" pipe. Unfortunately, buggy devices such as
+ * the BTC keyboard (ID 046e:5303) the request also affects
+ * Get_Report requests on the control pipe. In the worst
+ * case, if the device was put on idle for an indefinite
+ * amount of time (as we do below) and there are no input
+ * events to report, the Get_Report requests will just hang
+ * until we get a USB timeout. To avoid this, we temporarily
+ * establish a minimal idle time of 1ms. This shouldn't hurt
+ * bugfree devices and will cause a worst-case extra delay of
+ * 1ms for buggy ones.
+ */
+ usb_control_msg(hid->dev, usb_sndctrlpipe(hid->dev, 0),
+ HID_REQ_SET_IDLE, USB_TYPE_CLASS | USB_RECIP_INTERFACE, (1 <<
8),
+ hid->ifnum, NULL, 0, HZ * USB_CTRL_SET_TIMEOUT);
+
report_enum = hid->report_enum + HID_INPUT_REPORT;
list = report_enum->report_list.next;
while (list != &report_enum->report_list) {
@@ -1301,7 +1320,7 @@
if (len > hid->urbin->transfer_buffer_length)
hid->urbin->transfer_buffer_length = len < HID_BUFFER_SIZE ?
len : HID_BUFFER_SIZE;
usb_control_msg(hid->dev, usb_sndctrlpipe(hid->dev, 0),
- 0x0a, USB_TYPE_CLASS | USB_RECIP_INTERFACE, report->id,
+ HID_REQ_SET_IDLE, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
report->id,
hid->ifnum, NULL, 0, HZ * USB_CTRL_SET_TIMEOUT);
list = list->next;
}
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