On Fri, 1 Feb 2008, Xiaofan Chen wrote: > On Feb 1, 2008 11:17 PM, Alan Stern <[EMAIL PROTECTED]> wrote: > > On Thu, 31 Jan 2008, David Brownell wrote: > > > > > On Thursday 31 January 2008, Alan Stern wrote: > > > > The interesting difference lay in what Windows did when the Get-Max-LUN > > > > stalled. It sent a Clear-Halt request to endpoint 0! > > > > > > Yes that *is* strange! Considering that ep0 wasn't stalling ... > > > > No, ep0 did stall (at least, that's the way it looks from the SnoopyPro > > trace and that's what happened under Linux). This was in response to > > the Bulk-only-transport class-specific Get-Max-LUN request. Devices > > are permitted not to support that request if they have only one LUN. > > So I will think this is a "protocol stall" for endpoint 0. Am I right?
Yes. > > Right now usb-storage responds to this stall by clearing the halt > > feature from the bulk-in and bulk-out endpoints, not because the spec > > says to do so but because one ancient device (a ZIP-100) requires it. > > Now it looks as though we've found a device which can't handle it. > > Time for another quirk? > > If my previous assumption is correct, I will think the Windows driver behavior > can be said to be a bit strange since normally you do not need to clear halt > for protocol stall. I will think the Linux USB behavior is even stranger. > I know quite some USB devices which do not handle clear halt feature > request nicely. Linux does it only because that one device needs it. Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
