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authorAndiry Xu <andiry.xu@amd.com>2011-03-22 17:08:14 +0800
committerSarah Sharp <sarah.a.sharp@linux.intel.com>2011-04-13 16:57:37 -0700
commitc41136b05d3fb213a192f76a5688ff83687c1136 (patch)
tree4589319d5352f7e419145a25193fc78cf502f8c9 /drivers/usb/host/xhci-pci.c
parentfedd383e33f9ba9b91626f72c593ea327403bf59 (diff)
downloadlinux-stericsson-c41136b05d3fb213a192f76a5688ff83687c1136.tar.gz
xHCI: Implement AMD PLL quirk
This patch disable the optional PM feature inside the Hudson3 platform under the following conditions: 1. If an isochronous device is connected to xHCI port and is active; 2. Optional PM feature that powers down the internal Bus PLL when the link is in low power state is enabled. The PM feature needs to be disabled to eliminate PLL startup delays when the link comes out of low power state. The performance of DMA data transfer could be impacted if system delay were encountered and in addition to the PLL start up delays. Disabling the PM would leave room for unpredictable system delays in order to guarantee uninterrupted data transfer to isochronous audio or video stream devices that require time sensitive information. If data in an audio/video stream was interrupted then erratic audio or video performance may be encountered. AMD PLL quirk is already implemented in OHCI/EHCI driver. After moving the quirk code to pci-quirks.c and export them, xHCI driver can call it directly without having the quirk implementation in itself. Signed-off-by: Andiry Xu <andiry.xu@amd.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb/host/xhci-pci.c')
-rw-r--r--drivers/usb/host/xhci-pci.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index ceea9f33491c..a10494c2f3c7 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -114,6 +114,10 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
if (pdev->vendor == PCI_VENDOR_ID_NEC)
xhci->quirks |= XHCI_NEC_HOST;
+ /* AMD PLL quirk */
+ if (pdev->vendor == PCI_VENDOR_ID_AMD && usb_amd_find_chipset_info())
+ xhci->quirks |= XHCI_AMD_PLL_FIX;
+
/* Make sure the HC is halted. */
retval = xhci_halt(xhci);
if (retval)