Commit a70bcbc3 authored Oct 04, 2019 by Rick Tseng Committed by Greg Kroah-Hartman Oct 04, 2019

usb: xhci: wait for CNR controller not ready bit in xhci resume



NVIDIA 3.1 xHCI card would lose power when moving power state into D3Cold.
Thus we need to wait for CNR bit to clear in xhci resume, just as in
xhci init.

[Minor changes to comment and commit message -Mathias]
Cc: <stable@vger.kernel.org>
Signed-off-by: Rick Tseng <rtseng@nvidia.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/1570190373-30684-6-git-send-email-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 47f50d61

drivers/usb/host/xhci.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -1108,6 +1108,18 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
		hibernated = true;

		if (!hibernated) {
		/*
		* Some controllers might lose power during suspend, so wait
		* for controller not ready bit to clear, just as in xHC init.
		*/
		retval = xhci_handshake(&xhci->op_regs->status,
		STS_CNR, 0, 10 * 1000 * 1000);
		if (retval) {
		xhci_warn(xhci, "Controller not ready at resume %d\n",
		retval);
		spin_unlock_irq(&xhci->lock);
		return retval;
		}
		/* step 1: restore register */
		xhci_restore_registers(xhci);
		/* step 2: initialize command ring buffer */