On Tue, 24 Sep 2019, Ran Wang wrote: > Hi Greg, > > On Monday, September 23, 2019 19:07, Greg Kroah-Hartman wrote: > > > > On Mon, Sep 23, 2019 at 06:51:02PM +0800, Ran Wang wrote: > > > USB 2.0 Embedded Host PET Automated Test (CH6) 6.7.23 A-UUT > > > "Unsupported Device" Message require to stop enumerating device with > > > VID=0x1a0a PID=0x0201 and pop message to declare this device is not > > supported. > > > > Why is this a requirement? > > This comes from <USB On-The-Go and Embedded Host Automated Compliance Plan > for the On-The-Go& Embedded Host Supplement Revision2.0> How much do we care about our support for USB OTG? Isn't it dying off? > Below is related description I quote from it: > 6.7.23 A-UUT "Unsupported Device" Message > Purpose: This test verifies that an A-UUT produces a device non-supported error message > when a device it doesn't recognize, and does not support HNP, connects to it. > Applies to: All Targeted Hosts > Description: Get VBUS turned on, and connect to the A-UUT. Get enumerated and respond > as an unknown device not supporting HNP. Check that a suitable error message is generated. > Pass Criteria: Message "Unsupported Device"or similar is displayed on UUT > > 6.7.23.1 Test Procedure > 1. Start with cable still attached, PET applying 10�capacitance and 10k�pull-down > resistance between VBUS and ground, data lines not pulled up. > 2. Get VBUS turned on, using the method described in Section6.7.1. > 3. Wait for almost TB_SVLD_BCON max (1s - 0.1s = 0.9s) from VBUS reaching VOTG_SESS_VLD max. > 4. Connect PET using D+ pull-up. > 5. Allow A-UUT to enumerate PET, responding with a VID / PID combination not on the TPL > of the UUT and also with the OTG descriptor stating that it does not support HNP. > 6. Start 30s timer when Device Descriptor is read. > 7. Display Message "Click OK if 'Unsupported Device' indication displayed on UUT". > 8. If operator clicks OK before 30s timer expires, then UUT passes test. > 9. If 30selapses first, then UUT fails test. > 10. PET disconnects by removing any termination on the data lines, but leaves a capacitance of > 10�and a pull-down resistance of 10k�connected across VBUS. > 11. Wait 2s to allow disconnection to be detected. > End of Test. In fact, the system should respond the same way to any unrecognized device that doesn't support HNP, right? There's nothing special about these VID/PID values. > > And why those specific vid/pid values? What do they refer to? > > For step 5, we got the VID / PID number from USB IF certified lab(Allion.inc at Taiwang). Looks like > this is a reserved ID pair and will not be allocated to any vendor for their products. So it's hence used for this > case test (like saying: you should be able to pop a not-support message for this reserved VID&PID). Don't we do this already? Alan Stern
