Commits
Sarah Sharp committed e95829f474f
xhci: Switch PPT ports to EHCI on shutdown. The Intel desktop boards DH77EB and DH77DF have a hardware issue that can be worked around by BIOS. If the USB ports are switched to xHCI on shutdown, the xHCI host will send a spurious interrupt, which will wake the system. Some BIOS will work around this, but not all. The bug can be avoided if the USB ports are switched back to EHCI on shutdown. The Intel Windows driver switches the ports back to EHCI, so change the Linux xHCI driver to do the same. Unfortunately, we can't tell the two effected boards apart from other working motherboards, because the vendors will change the DMI strings for the DH77EB and DH77DF boards to their own custom names. One example is Compulab's mini-desktop, the Intense-PC. Instead, key off the Panther Point xHCI host PCI vendor and device ID, and switch the ports over for all PPT xHCI hosts. The only impact this will have on non-effected boards is to add a couple hundred milliseconds delay on boot when the BIOS has to switch the ports over from EHCI to xHCI. This patch should be backported to kernels as old as 3.0, that contain the commit 69e848c2090aebba5698a1620604c7dccb448684 "Intel xhci: Support EHCI/xHCI port switching." Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Reported-by: Denis Turischev <denis@compulab.co.il> Tested-by: Denis Turischev <denis@compulab.co.il> Cc: stable@vger.kernel.org