Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755455Ab3DYHMH (ORCPT ); Thu, 25 Apr 2013 03:12:07 -0400 Received: from g4t0017.houston.hp.com ([15.201.24.20]:3737 "EHLO g4t0017.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753207Ab3DYHMG (ORCPT ); Thu, 25 Apr 2013 03:12:06 -0400 From: "Li, Zhen-Hua" To: , , , Cc: , "Li, Zhen-Hua" Subject: [PATCH 1/1] driver,usb: Fix a warning in uhci-hcd driver Date: Thu, 25 Apr 2013 15:11:09 +0800 Message-Id: <1366873869-17446-1-git-send-email-zhen-hual@hp.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2200 Lines: 65 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 Signed-off-by: Tom Vaden --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/