Messages in this thread | | | Date | Thu, 15 May 2003 17:07:42 -0400 (EDT) | From | Alan Stern <> | Subject | Re: Test Patch: 2.5.69 Interrupt Latency |
| |
On 15 May 2003, Paul Fulghum wrote:
> I have a question about the wakeup_hc() code in general: > > when waking in response to a resume event, > the current code sets the USBCMD_FGR (force global resume) > and USBCMD_EGSM (enter global suspend mode) bits, > waits 20ms and clears both bits to start sending EOP signal. > > According to the datasheet, the controller itself > (not software) sets the FGR bit on detection of > a resume event. 20ms after the USBSTS_RD indication, > software should clear both the FGR and EGSM bits. > > My reading of this is that the line: > > outw(USBCMD_FGR | USBCMD_EGSM, io_addr + USBCMD); > > before the 20ms wait should not be necessary. > > Am I reading this correctly?
I interpret it the same way as you. I tried removing that line from the driver, and it continued to work just fine. So it looks like you are right.
Alan Stern
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |