[Vivid][SRU][PATCH] xhci: call BIOS workaround to enable runtime suspend on Intel Braswell

Phidias Chiang phidias.chiang at canonical.com
Tue Sep 1 10:01:32 UTC 2015


From: Mathias Nyman <mathias.nyman at linux.intel.com>

BugLink: http://bugs.launchpad.net/bugs/1489292

Intel xhci hw that require XHCI_PME_STUCK quirk have as default disabled
xhci from going to D3 state in runtime suspend. Driver needs to verify
it can deal with the hw by calling an ACPI _DSM method to get D3 enabled.

Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit c3c5819a350952439c3198aa46581f9e4c46557f)
Signed-off-by: Phidias Chiang <phidias.chiang at canonical.com>
Reviewed-by: Wen-chien Jesse Sung <jesse.sung at canonical.com>
---
 drivers/usb/host/xhci-pci.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 2af32e2..5a00b6a 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -23,6 +23,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/acpi.h>
 
 #include "xhci.h"
 #include "xhci-trace.h"
@@ -183,6 +184,19 @@ static void xhci_pme_quirk(struct xhci_hcd *xhci)
 	readl(reg);
 }
 
+#ifdef CONFIG_ACPI
+static void xhci_pme_acpi_rtd3_enable(struct pci_dev *dev)
+{
+	static const u8 intel_dsm_uuid[] = {
+		0xb7, 0x0c, 0x34, 0xac,	0x01, 0xe9, 0xbf, 0x45,
+		0xb7, 0xe6, 0x2b, 0x34, 0xec, 0x93, 0x1e, 0x23,
+	};
+	acpi_evaluate_dsm(ACPI_HANDLE(&dev->dev), intel_dsm_uuid, 3, 1, NULL);
+}
+#else
+	static void xhci_pme_acpi_rtd3_enable(struct pci_dev *dev) { }
+#endif /* CONFIG_ACPI */
+
 /* called during probe() after chip reset completes */
 static int xhci_pci_setup(struct usb_hcd *hcd)
 {
@@ -262,6 +276,9 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 			HCC_MAX_PSA(xhci->hcc_params) >= 4)
 		xhci->shared_hcd->can_do_streams = 1;
 
+	if (xhci->quirks & XHCI_PME_STUCK_QUIRK)
+		xhci_pme_acpi_rtd3_enable(dev);
+
 	/* USB-2 and USB-3 roothubs initialized, allow runtime pm suspend */
 	pm_runtime_put_noidle(&dev->dev);
 
-- 
2.1.4





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