Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | Re: 2.5.69 Interrupt Latency | Date | Fri, 09 May 2003 23:06:05 +0200 |
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Paul Fulghum wrote:
> One machine (server) was using usb-uhci and > the other (laptop) was using usb-ohci. > > So it looks like something with USB in 2.5.68-bk11
The change below was part of 2.5.68-bk11, and adds a 20ms delay to the uhci interrupt handler. Could that be the culprit?
Arnd <><
ChangeSet 1.1042.1.129 2003/04/29 15:30:31 stern@rowland.harvard.edu [PATCH] USB: Minor patch for uhci-hcd.c --- 1.32/drivers/usb/host/uhci-hcd.c Mon Apr 14 11:51:40 2003 +++ 1.33/drivers/usb/host/uhci-hcd.c Fri Apr 18 13:37:24 2003 @@ -1283,7 +1283,8 @@ } if (last_urb) { - *end = (last_urb->start_frame + last_urb->number_of_packets) & 1023; + *end = (last_urb->start_frame + last_urb->number_of_packets * + last_urb->interval) & (UHCI_NUMFRAMES-1); ret = 0; } else ret = -1; /* no previous urb found */ @@ -1933,9 +1934,10 @@ dbg("%x: suspend_hc", io_addr); - outw(USBCMD_EGSM, io_addr + USBCMD); - uhci->is_suspended = 1; + smp_wmb(); + + outw(USBCMD_EGSM, io_addr + USBCMD); } static void wakeup_hc(struct uhci_hcd *uhci) @@ -1945,6 +1947,9 @@ dbg("%x: wakeup_hc", io_addr); + /* Global resume for 20ms */ + outw(USBCMD_FGR | USBCMD_EGSM, io_addr + USBCMD); + wait_ms(20); outw(0, io_addr + USBCMD); /* wait for EOP to be sent */ @@ -1965,7 +1970,7 @@ int i; for (i = 0; i < uhci->rh_numports; i++) - connection |= (inw(io_addr + USBPORTSC1 + i * 2) & 0x1); + connection |= (inw(io_addr + USBPORTSC1 + i * 2) & USBPORTSC_CCS); return connection; } - 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/
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