On Thu, 29 Aug 2013, Udo van den Heuvel wrote:
> On 2013-08-28 21:37, Alan Stern wrote:
> >>> No, if you unload the ohci-hcd driver then the webcam won't be used.
> >>> Are you certain that merely stopping the daemon program will prevent
> >>> the problem?
> >>
> >> Quite certain but retesting can confirm that.
> >
> > Maybe without activity, the OHCI controller goes into suspend. You can
> > prevent it by doing:
> >
> > echo on >/sys/bus/pci/devices/0000:00:13.1/usb?/power/control
>
> /sys/bus/pci/devices/0000:00:13.0 has a file irq containing 18.
> subdirectory usb8 under there has no power/control subdir/file.
> Is this a configuration issue or kernel version difference?
It could be a config issue. The file will be present only if
CONFIG_PM_RUNTIME is enabled.
> > By the way, since you switched to the new computer, are there any
> > devices attached to this USB bus other than the webcam?
>
> The wired mouse (logitech M-BD58) is connected via usb.
Is it connected to the 0000:00:13.1 controller or to the 0000:00:13.0
controller?
> > Also, at one point you had a second webcam attached to a different OHCI
> > controller, as well as a Bluetooth device and a USB-serial device.
> > Are they still present?
>
> Nope. Presently not connected.
>
> I'll have some hubs this weekend to play with.
In the meantime, here is a diagnostic patch you can try out.
Alan Stern
Index: usb-3.11/drivers/usb/host/ohci-hcd.c
===================================================================
--- usb-3.11.orig/drivers/usb/host/ohci-hcd.c
+++ usb-3.11/drivers/usb/host/ohci-hcd.c
@@ -592,7 +592,10 @@ static int ohci_run (struct ohci_hcd *oh
u32 mask, val;
int first = ohci->fminterval == 0;
struct usb_hcd *hcd = ohci_to_hcd(ohci);
+ static int alan_id;
+ ohci->alan_time = jiffies;
+ ohci->alan_limit = (++alan_id) * 1000;
ohci->rh_state = OHCI_RH_HALTED;
/* boot firmware should have set this up (5.1.1.3.1) */
@@ -810,6 +813,20 @@ static irqreturn_t ohci_irq (struct usb_
return IRQ_HANDLED;
}
+ if (ohci->alan_count < 0)
+ return IRQ_NOTMINE;
+ else if (time_after(jiffies, ohci->alan_time)) {
+ ohci->alan_time = jiffies + HZ/10;
+ ohci->alan_count = 0;
+ } else if (++ohci->alan_count > ohci->alan_limit) {
+ ohci_info(ohci, "Too many interrupts %d, disabling\n",
+ ohci->alan_limit);
+ ohci->alan_count = -1;
+ ohci_writel(ohci, ~0, ®s->intrdisable);
+ ohci_writel(ohci, ~0, ®s->intrstatus);
+ return IRQ_NOTMINE;
+ }
+
/* We only care about interrupts that are enabled */
ints &= ohci_readl(ohci, ®s->intrenable);
Index: usb-3.11/drivers/usb/host/ohci-hub.c
===================================================================
--- usb-3.11.orig/drivers/usb/host/ohci-hub.c
+++ usb-3.11/drivers/usb/host/ohci-hub.c
@@ -218,7 +218,8 @@ __acquires(ohci->lock)
skip_resume:
/* interrupts might have been disabled */
- ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
+ if (ohci->alan_count >= 0)
+ ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
if (ohci->ed_rm_list)
ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
Index: usb-3.11/drivers/usb/host/ohci.h
===================================================================
--- usb-3.11.orig/drivers/usb/host/ohci.h
+++ usb-3.11/drivers/usb/host/ohci.h
@@ -415,6 +415,10 @@ struct ohci_hcd {
struct ed *ed_to_check;
unsigned zf_delay;
+ unsigned long alan_time;
+ int alan_count;
+ int alan_limit;
+
#ifdef DEBUG
struct dentry *debug_dir;
struct dentry *debug_async;
--
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