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

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There is a function  wait_for_HP() in uhci-hub.c. In this
patch, it is used in suspend_rh(),  I think this can be a
solution. And I have tested this patch, it can fix the bug.

I think there is another patch needed. As Alan said in another
mail, in the UHCI_RH_RUNNING_NODEVS case, it should not be stopped
if the uhci device is HP iLo virtual usb.


Thanks
Zhen-Hua

On 04/26/2013 03:38 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 the HP iLo virtual usb
device requires a longer delay.

Signed-off-by: Li, Zhen-Hua <zhen-hual@xxxxxx>
---
  drivers/usb/host/uhci-hcd.c |    5 +++++
  drivers/usb/host/uhci-hub.c |   12 +++++++-----
  2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 4a86b63..af30517 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -355,6 +355,11 @@ __acquires(uhci->lock)
  		if (uhci->dead)
  			return;
  	}
+
+	/* HP's iLo Virtual USB Controller requires a longer delay. */
+	if (uhci->wait_for_hp)
+		wait_for_HP(uhci, USBSTS, USBSTS_HCH, 1000);
+
  	if (!(uhci_readw(uhci, USBSTS) & USBSTS_HCH))
  		dev_warn(uhci_dev(uhci), "Controller not stopped yet!\n");
diff --git a/drivers/usb/host/uhci-hub.c b/drivers/usb/host/uhci-hub.c
index f87bee6..c3f772c 100644
--- a/drivers/usb/host/uhci-hub.c
+++ b/drivers/usb/host/uhci-hub.c
@@ -120,14 +120,15 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
  }
/* Wait for the UHCI controller in HP's iLO2 server management chip.
- * It can take up to 250 us to finish a reset and set the CSC bit.
+ * It can take up to max_wait us to finish the operation.
   */
-static void wait_for_HP(struct uhci_hcd *uhci, unsigned long port_addr)
+static void wait_for_HP(struct uhci_hcd *uhci, unsigned long port_addr,
+		u16 status, int max_wait)
  {
  	int i;
- for (i = 10; i < 250; i += 10) {
-		if (uhci_readw(uhci, port_addr) & USBPORTSC_CSC)
+	for (i = 10; i < max_wait; i += 10) {
+		if (uhci_readw(uhci, port_addr) & status)
  			return;
  		udelay(10);
  	}
@@ -151,7 +152,8 @@ static void uhci_check_ports(struct uhci_hcd *uhci)
  				/* HP's server management chip requires
  				 * a longer delay. */
  				if (uhci->wait_for_hp)
-					wait_for_HP(uhci, port_addr);
+					wait_for_HP(uhci, port_addr,
+						USBPORTSC_CSC, 250);
/* If the port was enabled before, turning
  				 * reset on caused a port enable change.

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