Messages in this thread | | | Date | Wed, 25 Jan 2017 15:38:29 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v5 1/4] usb: dbc: early driver for xhci debug capability |
| |
On Wed, Jan 25, 2017 at 08:27:38PM +0800, Lu Baolu wrote: > In my driver, udelay() is mostly used to handle time out. > > Xdbc hides most USB things in its firmware. Early printk driver only needs > to setup the registers/data structures and wait until link ready or time out. > Without udelay(), I have no means to convert the polling times into waiting > time.
What is timeout and why? If there is an error other than !ready, I would expect the hardware to inform you of this through another status bit, no?
So why can't you poll indefinitely for either ready or error?
| |