[PATCH] USB: ohci-at91: add a reset function to fix race condition

From: Nicolas Ferre
Date: Wed May 09 2012 - 04:49:30 EST


A possible race condition appears because we are not initializing
the ohci->regs before calling usb_hcd_request_irqs().
We move the call to ohci_init() in hcd->driver->reset() instead of
hcd->driver->start() to fix this.
This was experienced when we share the same IRQ line between OHCI and EHCI
controllers.

Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
Tested-by: Christian Eggers <christian.eggers@xxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
---
drivers/usb/host/ohci-at91.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index 13ebeca..55d3d64 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -223,7 +223,7 @@ static void __devexit usb_hcd_at91_remove(struct usb_hcd *hcd,
/*-------------------------------------------------------------------------*/

static int __devinit
-ohci_at91_start (struct usb_hcd *hcd)
+ohci_at91_reset (struct usb_hcd *hcd)
{
struct at91_usbh_data *board = hcd->self.controller->platform_data;
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
@@ -233,6 +233,14 @@ ohci_at91_start (struct usb_hcd *hcd)
return ret;

ohci->num_ports = board->ports;
+ return 0;
+}
+
+static int __devinit
+ohci_at91_start (struct usb_hcd *hcd)
+{
+ struct ohci_hcd *ohci = hcd_to_ohci (hcd);
+ int ret;

if ((ret = ohci_run(ohci)) < 0) {
err("can't start %s", hcd->self.bus_name);
@@ -418,6 +426,7 @@ static const struct hc_driver ohci_at91_hc_driver = {
/*
* basic lifecycle operations
*/
+ .reset = ohci_at91_reset,
.start = ohci_at91_start,
.stop = ohci_stop,
.shutdown = ohci_shutdown,
--
1.7.10

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