From b09bc6cbae4dd3a2d35722668ef2c502a7b8b093 Mon Sep 17 00:00:00 2001 From: Andiry Xu Date: Fri, 14 Nov 2008 11:42:29 +0800 Subject: [PATCH] USB: fix SB700 usb subsystem hang bug This patch is required for AMD SB700 south bridge revision A12 and A13 to avoid USB subsystem hang symptom. The USB subsystem hang symptom is observed when the system has multiple USB devices connected to it. In some cases a USB hub may be required to observe this symptom. This patch works around the problem by correcting the internal register setting that will help by changing the behavior of the internal logic to avoid the USB subsystem hang issue. The change in the behavior of the logic does not impact the normal operation of the USB subsystem. Reported-by: Volker Armin Hemmann Tested-by: Volker Armin Hemmann Signed-off-by: Andiry Xu Signed-off-by: Libin Yang Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-pci.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c index c46a58f9181d..9d0ea573aef6 100644 --- a/drivers/usb/host/ehci-pci.c +++ b/drivers/usb/host/ehci-pci.c @@ -66,6 +66,8 @@ static int ehci_pci_setup(struct usb_hcd *hcd) { struct ehci_hcd *ehci = hcd_to_ehci(hcd); struct pci_dev *pdev = to_pci_dev(hcd->self.controller); + struct pci_dev *p_smbus; + u8 rev; u32 temp; int retval; @@ -166,6 +168,25 @@ static int ehci_pci_setup(struct usb_hcd *hcd) pci_write_config_byte(pdev, 0x4b, tmp | 0x20); } break; + case PCI_VENDOR_ID_ATI: + /* SB700 old version has a bug in EHCI controller, + * which causes usb devices lose response in some cases. + */ + if (pdev->device == 0x4396) { + p_smbus = pci_get_device(PCI_VENDOR_ID_ATI, + PCI_DEVICE_ID_ATI_SBX00_SMBUS, + NULL); + if (!p_smbus) + break; + rev = p_smbus->revision; + if ((rev == 0x3a) || (rev == 0x3b)) { + u8 tmp; + pci_read_config_byte(pdev, 0x53, &tmp); + pci_write_config_byte(pdev, 0x53, tmp | (1<<3)); + } + pci_dev_put(p_smbus); + } + break; } ehci_reset(ehci); -- 2.20.1