> From: Paul Zimmerman > > > From: Felipe Balbi [mailto:balbi@xxxxxx] > > > > On Wed, Sep 24, 2014 at 09:40:37PM -0500, Felipe Balbi wrote: > > > On Thu, Sep 25, 2014 at 01:37:05AM +0000, Paul Zimmerman wrote: > > > > > > > Then, after the host cleared the halt, the gadget apparently sent the > > > > > > > data that _should_ have been sent previously. The host was expecting > > > > > > > to receive the CSW at this point, so there was an overflow error. > > > > > > > That's what caused the host to perform a reset. > > > > > > > > > > > > > > Evidently this UDC implements the set_halt method incorrectly. > > > > > > > According to the kerneldoc for usb_ep_set_halt: > > > > > > > > > > > > > > * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any > > > > > > > * transfer requests are still queued, or if the controller hardware > > > > > > > * (usually a FIFO) still holds bytes that the host hasn't collected. > > > > > > > > > > > > damn old bugs :-) I'll fix that up and Cc stable. > > > > > > > > > > alright fixed. Below you can see a combined diff which I'll still split > > > > > into patches so they can be applied properly. > > > > > > > > [ snipped patch which grubs around in the GDBGFIFOSPACE registers ] > > > > > > > > Ick. That shouldn't be necessary. The Synopsys vendor driver works > > > > > > you need to make sure that both there are no pending transfers and FIFO > > > is empty in case of IN endpoints. Databook itself says (sorry, forgot > > > the section and no access to the docs right now) that to figure out if > > > the FIFO is empty, application can use GDBGFIFOSPACE. Do you have any > > > better ideas ? > > > > oh, and btw... I only noticed the failure with Linux. I mentioned that > > it, though flakey during start, worked very stably against Mac OS X. > > Perhaps Windows is also more forgiving ? > > Yeah, I see you said it only fails with 3.17-rc on an embedded platform > you have. Can you say which platform that is? Do you know whose xHCI > controller it uses? > > > Can you share a little more details on what you guys did to get it to > > work without making sure FIFO is empty ? I can't really understand how > > you'd cover all cases otherwise... > > See my other email, I will try to find the fix for the similar issue > that we saw. OK, it looks like that issue is not related to this one. We were accidentally setting the Stream Capable bit in the endpoint configuration for all bulk EPs, not just stream-enabled ones. That caused several strange behaviors, including the Set Stall command not working. -- Paul -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
