Hi, On Thu, Jul 25, 2013 at 05:33:48PM -0400, Alan Stern wrote: > > On Thu, Jul 25, 2013 at 03:44:20PM -0400, Alan Stern wrote: > > > On Thu, 25 Jul 2013, Greg KH wrote: > > > > > > > On Tue, Jul 02, 2013 at 08:13:52PM -0700, Jack Pham wrote: > > > > > From: Manu Gautam <mgautam@xxxxxxxxxxxxxx> > > > > > > > > > > The USB Embedded High-speed Host Electrical Test (EHSET) defines the > > > > > SINGLE_STEP_SET_FEATURE test as follows: > > > > > > > > > > 1) The host enumerates the test device with VID:0x1A0A, PID:0x0108 > > > > > 2) The host sends the SETUP stage of a GetDescriptor(Device) > > > > > 3) The device ACKs the request > > > > > 4) The host issues SOFs for 15 seconds allowing the test operator to > > > > > raise the scope trigger just above the SOF voltage level > > > > > 5) The host sends the IN packet > > > > > 6) The device sends data in response, triggering the scope > > > > > 7) The host sends an ACK in response to the data > > > > > > > > > > This patch adds additional handling to the EHCI hub driver and allows > > > > > the EHSET driver to initiate this test mode by issuing a a SetFeature > > > > > request to the root hub with a Test Selector value of 0x06. From there > > > > > it mimics ehci_urb_enqueue() but separately submits QTDs for the > > > > > SETUP and DATA/STATUS stages in order to insert a delay in between. > > > > > > > > > > Signed-off-by: Manu Gautam <mgautam@xxxxxxxxxxxxxx> > > > > > Signed-off-by: Jack Pham <jackp@xxxxxxxxxxxxxx> > > > > > > > > Alan, any thoughts about this patch? > > > > > > Sorry, this slipped my mind. > > > > > > It looks okay. I haven't tested it yet (and it's so specialized that > > > it probably will never receive very much testing). It is somewhat > > > fragile, in that it copies part of usbcore into ehci-hcd; updates to > > > the core will have to be mirrored in the driver. > > > > > > On the other hand, there's no real reason to reject it, and it could > > > end up helping people who want to test new USB devices. So... > > > > > > Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > > > Wait a minute, didn't we discuss a while back that these test features > > should be built into usbcore so that we could have a usbcv clone for > > linux ? > > There's no way this can be built into the core. This test requires the > behavior of the host controller to be modified at a low level > (introducing a 15-second delay between the Setup and Data stages of a > control transfer). Only the HCD can do that. heh, it doesn't need to be entirely in the core. Core could have the generic calls and HCDs could implement some callbacks, but I think quite a bit of the code will be similar if we implement the same thing on all HCDs. > Besides, doesn't USB-CV install its own version of Windows' EHCI driver > while it runs its tests? IIRC only USB20CV, the new USB30CV (which also tests USB2) doesn't do that. -- balbi
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