Hi Matthias,

On Mar 18, 2018, at 11:11 PM, Kai-Heng Feng kai.heng.feng@canonical.com wrote:

The Dell Inspiron 5775 is a Raven Ridge. The Enable Slot command timed out when a USB device gets plugged: [ 212.156326] xhci_hcd 0000:03:00.3: Error while assigning device slot ID [ 212.156340] xhci_hcd 0000:03:00.3: Max number of devices this xHCI host supports is 64. [ 212.156348] usb usb2-port3: couldn't allocate usb_device

AMD suggests that a delay before xHC suspends can fix the issue.

I can confirm it fixes the issue, so use the suspend delay quirk for Raven Ridge's xHC.

I am hoping this patch can get merged in v4.17...

Thanks, Kai-Heng

Cc: stable@vger.kernel.org Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com

---

drivers/usb/host/xhci-pci.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index d9f831b67e57..93ce34bce7b5 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -126,7 +126,10 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci) if (pdev->vendor == PCI_VENDOR_ID_AMD && usb_amd_find_chipset_info()) xhci->quirks |= XHCI_AMD_PLL_FIX;

• if (pdev->vendor == PCI_VENDOR_ID_AMD && pdev->device == 0x43bb)

• if (pdev->vendor == PCI_VENDOR_ID_AMD &&

• (pdev->device == 0x15e0 ||
  

•  pdev->device == 0x15e1 ||
  

•  pdev->device == 0x43bb))
  

  xhci->quirks |= XHCI_SUSPEND_DELAY;

  if (pdev->vendor == PCI_VENDOR_ID_AMD)

-- 2.15.1