2013-04-25 07:12:07

by Li, ZhenHua

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

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 <[email protected]>
Signed-off-by: Tom Vaden <[email protected]>
---
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);
--
1.7.10.4

2013-04-25 07:13:31

by Li, ZhenHua

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

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 <[email protected]>
> Signed-off-by: Tom Vaden <[email protected]>
> ---
> 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);

2013-04-25 14:33:40

by Alan Stern

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

On Thu, 25 Apr 2013, ZhenHua wrote:

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

You did not answer my question: How long does it take for the iLo
controller to go into suspend?

Alan Stern

2013-04-25 14:56:29

by Alan Stern

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

On Thu, 25 Apr 2013, Alan Stern wrote:

> On Thu, 25 Apr 2013, ZhenHua wrote:
>
> > I send out this patch for the second time.
> > Changed try to int. And modified the comment.
>
> You did not answer my question: How long does it take for the iLo
> controller to go into suspend?

Oops, sorry, I see now that you did answer the question in a different
email message.

Alan Stern