USB: OHCI: disable RHSC inside interrupt handler
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>
diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index 99357b9..1e5ed3b 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -41,7 +41,11 @@
{
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 @@
{
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 @@
}
}
- /* 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 @@
* 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;