Re: [PATCH 1/1] driver,usb: Fix a warning in uhci-hcd driver

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I send out this patch for the second time.
Changed try to int. And modified the comment.

On 04/25/2013 03:11 PM, Li, Zhen-Hua wrote:
This patch is trying to fix this bug on SLES11 SP2:
     https://bugzilla.novell.com/show_bug.cgi?id=817035

On a large HP system with 64T memory and 60 logical cpus, when usb
driver inits the iLo Virtual USB Controller, there comes a warning
"Controller not stopped yet!". It is because driver does not wait
enough time. So driver should wait and retry if found controller
  not stopped.

Signed-off-by: Li, Zhen-Hua <zhen-hual@xxxxxx>
Signed-off-by: Tom Vaden <tom.vaden@xxxxxx>
---
  drivers/usb/host/uhci-hcd.c |   17 ++++++++++++++++-
  1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 4a86b63..d592e22 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -277,6 +277,9 @@ static int global_suspend_mode_is_broken(struct uhci_hcd *uhci)
  		uhci->global_suspend_mode_is_broken(uhci) : 0;
  }
+#define UHCI_SUSPENDRH_RETRY_MAX 10
+#define UHCI_SUSPENDRH_RETRY_DELAY    100
+
  static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
  __releases(uhci->lock)
  __acquires(uhci->lock)
@@ -284,6 +287,8 @@ __acquires(uhci->lock)
  	int auto_stop;
  	int int_enable, egsm_enable, wakeup_enable;
  	struct usb_device *rhdev = uhci_to_hcd(uhci)->self.root_hub;
+	int try;
+	u16 stopped;
auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
  	dev_dbg(&rhdev->dev, "%s%s\n", __func__,
@@ -355,7 +360,17 @@ __acquires(uhci->lock)
  		if (uhci->dead)
  			return;
  	}
-	if (!(uhci_readw(uhci, USBSTS) & USBSTS_HCH))
+
+	for (try = 0; try < UHCI_SUSPENDRH_RETRY_MAX; try++) {
+		/* For some devices, for example, HP iLo usb controller,
+		 * we need to wait for more time and retry.
+		 */
+		stopped = uhci_readw(uhci, USBSTS) & USBSTS_HCH;
+		if (stopped)
+			break;
+		udelay(UHCI_SUSPENDRH_RETRY_DELAY);
+	}
+	if (!stopped)
  		dev_warn(uhci_dev(uhci), "Controller not stopped yet!\n");
uhci_get_current_frame_number(uhci);

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