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USB: OHCI: disable RHSC inside interrupt handler

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This patch (as808b) moves the Root Hub Status Change interrupt-disable
code in ohci-hcd back into the interrupt handler proper, to avoid the
chance of adverse interactions with mediocre hardware implementations.

It also deletes the root-hub status timer from within the interrupt-enable
routine.  There's no need to poll for status any more once interrupts are
re-enabled.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2006-10-27 10:33:11 -04:00 committed by Greg Kroah-Hartman
parent b1878440d4
commit 052ac01aeb
2 changed files with 18 additions and 16 deletions
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10
drivers/usb/host/ohci-hcd.c
View file

@ -729,6 +729,16 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd)
ohci->next_statechange = jiffies + STATECHANGE_DELAY;
ohci_writel(ohci, OHCI_INTR_RD | OHCI_INTR_RHSC,
&regs->intrstatus);
/* NOTE: Vendors didn't always make the same implementation
* choices for RHSC. Many followed the spec; RHSC triggers
* on an edge, like setting and maybe clearing a port status
* change bit. With others it's level-triggered, active
* until khubd clears all the port status change bits. We'll
* always disable it here and rely on polling until khubd
* re-enables it.
*/
ohci_writel(ohci, OHCI_INTR_RHSC, &regs->intrdisable);
usb_hcd_poll_rh_status(hcd);
}

24
drivers/usb/host/ohci-hub.c
View file

@ -41,7 +41,11 @@ static void ohci_rhsc_enable (struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
spin_lock_irq(&ohci->lock);
if (!ohci->autostop)
del_timer(&hcd->rh_timer); /* Prevent next poll */
ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
spin_unlock_irq(&ohci->lock);
}
#define OHCI_SCHED_ENABLES \
@ -348,7 +352,7 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int i, changed = 0, length = 1;
int any_connected = 0, rhsc_enabled = 1;
int any_connected = 0;
unsigned long flags;
spin_lock_irqsave (&ohci->lock, flags);
@ -389,19 +393,6 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
}
}
/* NOTE: vendors didn't always make the same implementation
* choices for RHSC. Sometimes it triggers on an edge (like
* setting and maybe clearing a port status change bit); and
* it's level-triggered on other silicon, active until khubd
* clears all active port status change bits. If it's still
* set (level-triggered) we must disable it and rely on
* polling until khubd re-enables it.
*/
if (ohci_readl (ohci, &ohci->regs->intrstatus) & OHCI_INTR_RHSC) {
ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrdisable);
(void) ohci_readl (ohci, &ohci->regs->intrdisable);
rhsc_enabled = 0;
}
hcd->poll_rh = 1;
/* carry out appropriate state changes */
@ -412,7 +403,8 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
* and RHSC is enabled */
if (!ohci->autostop) {
if (any_connected) {
if (rhsc_enabled)
if (ohci_readl(ohci, &ohci->regs->intrenable) &
OHCI_INTR_RHSC)
hcd->poll_rh = 0;
} else {
ohci->autostop = 1;