[PATCH 2/4] xhci: Add quirk to reset host back to default state at shutdown

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From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>

Systems based on Alder Lake P see significant boot time delay if
boot firmware tries to control usb ports in unexpected link states.

This is seen with self-powered usb devices that survive in U3 link
suspended state over S5.

A more generic solution to power off ports at shutdown was attempted in
commit 83810f84ecf1 ("xhci: turn off port power in shutdown")
but it caused regression.

Add host specific XHCI_RESET_TO_DEFAULT quirk which will reset host and
ports back to default state in shutdown.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
 drivers/usb/host/xhci-pci.c |  4 ++++
 drivers/usb/host/xhci.c     | 10 ++++++++--
 drivers/usb/host/xhci.h     |  1 +
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 6dd3102749b7..fbbd547ba12a 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -257,6 +257,10 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	     pdev->device == PCI_DEVICE_ID_INTEL_DNV_XHCI))
 		xhci->quirks |= XHCI_MISSING_CAS;
 
+	if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
+	    pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_PCH_XHCI)
+		xhci->quirks |= XHCI_RESET_TO_DEFAULT;
+
 	if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
 	    (pdev->device == PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_XHCI ||
 	     pdev->device == PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_XHCI ||
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 5176765c4013..79d7931c048a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -810,9 +810,15 @@ void xhci_shutdown(struct usb_hcd *hcd)
 
 	spin_lock_irq(&xhci->lock);
 	xhci_halt(xhci);
-	/* Workaround for spurious wakeups at shutdown with HSW */
-	if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
+
+	/*
+	 * Workaround for spurious wakeps at shutdown with HSW, and for boot
+	 * firmware delay in ADL-P PCH if port are left in U3 at shutdown
+	 */
+	if (xhci->quirks & XHCI_SPURIOUS_WAKEUP ||
+	    xhci->quirks & XHCI_RESET_TO_DEFAULT)
 		xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
+
 	spin_unlock_irq(&xhci->lock);
 
 	xhci_cleanup_msix(xhci);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index c0964fe8ac12..cc084d9505cd 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1897,6 +1897,7 @@ struct xhci_hcd {
 #define XHCI_BROKEN_D3COLD	BIT_ULL(41)
 #define XHCI_EP_CTX_BROKEN_DCS	BIT_ULL(42)
 #define XHCI_SUSPEND_RESUME_CLKS	BIT_ULL(43)
+#define XHCI_RESET_TO_DEFAULT	BIT_ULL(44)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.25.1




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