On Fri, 9 Jan 2015, Peter Chen wrote: > For chipidea, its resume sequence is not-EHCI compatible, see > below description for FPR at portsc. So in order to send SoF in > time for remote wakeup sequence(within 3ms), the RUN/STOP bit must > be set before the resume signal is ended, but the usb resume > code may run after resume signal is ended, so we had to set it > at suspend path. > > Force Port Resume - RW. Default = 0b. > 1= Resume detected/driven on port. > 0=No resume (K-state) detected/driven on port. > Host mode: > Software sets this bit to one to drive resume signaling. The Controller sets this bit to '1' if > a J-to-K transition is detected while the port is in the Suspend state. When this bit > transitions to a '1' because a J-to-K transition is detected, the Port Change Detect bit in > the USBSTS register is also set to '1'. This bit will automatically change to '0' after the > resume sequence is complete. This behavior is different from EHCI where the controller > driver is required to set this bit to a '0' after the resume duration is timed in the driver. > Note that when the controller owns the port, the resume sequence follows the defined > > sequence documented in the USB Specification Revision 2.0. The resume signaling > (Full-speed 'K') is driven on the port as long as this bit remains a '1'. This bit will remain > a '1' until the port has switched to idle. Writing a '0' has no affect because the port > controller will time the resume operation, clear the bit and the port control state switches > to HS or FS idle. > This field is '0' if Port Power(PP) is '0' in host mode. > > This bit is not-EHCI compatible. > > Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> -- 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
