diff mbox series

[5/8] usb: xhci: wait for CNR controller not ready bit in xhci resume

Message ID 1570190373-30684-6-git-send-email-mathias.nyman@linux.intel.com (mailing list archive)
State Superseded
Commit a70bcbc322837eda1ab5994d12db941dc9733a7d
Headers show
Series xhci fixes for usb-linus | expand

Commit Message

Mathias Nyman Oct. 4, 2019, 11:59 a.m. UTC 
From: Rick Tseng <rtseng@nvidia.com>

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>
---
 drivers/usb/host/xhci.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index aec69d294973..fe8f9ff58015 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -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 */