Yes, it's ok. Thank you.
Nevertheless, I think I will try to find out exactly what's happening.
2012/4/26 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>:
> On Thu, 26 Apr 2012, Calin Demian wrote:
>
>> I don't know how, but adding the following line in function
>> quirk_usb_handoff_ohci makes the system work fine:
>>
>> /* reset requires max 10 us delay */
>> + udelay(1);
>> for (cnt = 30; cnt > 0; --cnt) { /* ... allow extra time */
>> if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
>>
>> I observed thad the condition in the for loop is allways true, so the
>> delay inside the loop is never executed.
>> With the unmodified source, the execution doesn't stop at this point
>> but at the next readl (I tried inserting printk and readl instructions
>> after the writel which restores the fminterval and the execution
>> stopped before exiting quirk_usb_handoff_ohci).
>> I don't know how it relates to the ACPI message... (see bug 43073 in
>> bugzilla.kernel.org).
>
> I don't know just what the problem is either, but there's nothing wrong
> with delaying startup by 1 us. In fact, all we have to do is reorder
> the statements within the loop. Is this patch okay for you?
>
> Alan Stern
>
>
>
> Index: usb-3.4/drivers/usb/host/pci-quirks.c
> ===================================================================
> --- usb-3.4.orig/drivers/usb/host/pci-quirks.c
> +++ usb-3.4/drivers/usb/host/pci-quirks.c
> @@ -520,9 +520,10 @@ static void __devinit quirk_usb_handoff_
>
> /* reset requires max 10 us delay */
> for (cnt = 30; cnt > 0; --cnt) { /* ... allow extra time */
> + /* Some controllers enable HCR too soon, so always delay 1 us */
> + udelay(1);
> if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
> break;
> - udelay(1);
> }
> writel(fminterval, base + OHCI_FMINTERVAL);
>
>
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