On Fri, 25 Jan 2019, Bin Liu wrote: > On Thu, Jan 24, 2019 at 09:47:02PM +0300, Matwey V. Kornilov wrote: > > By the way, why do we need to store the qh in urb->hcpriv? > > qh can always be accessible through urb->ep->hcpriv > > Wouldn't it be better to drop entire urb->hcpriv usage? > > I am not sure why. The code is there since the first commit in a decade > ago. But I tend to agree with you. > > In a quick search for urb->hcpriv and urb->ep->hcpriv, based on the > usage in core/hcd.c, it seems to me that urb->hcpriv should not be > changed in each controller driver, but I see both have been used in most > controller drivers. I will leave this to others to educate me. In some of the older HCDs, urb->hcpriv != NULL is used to indicate that urb is on an endpoint queue. Perhaps that usage was copied. Alan Stern
