[PATCH v3] usb: host: xhci-plat: Iterate over parent nodes for finding quirks

[Anurag Kumar Vulisha]

In xhci_plat_probe() both sysdev and pdev->dev are being used
for finding quirks. There are some drivers(like dwc3 host.c)
which adds quirks(like usb3-lpm-capable) into pdev and the logic
present in xhci_plat_probe() checks for quirks in either sysdev
or pdev for finding the quirks. Because of this logic, some of
the quirks are getting missed(usb3-lpm-capable quirk added by dwc3
host.c driver is getting missed).This patch fixes this by iterating
over all the available parents for finding the quirks. In this way
all the quirks which are present in child or parent are correctly
updated.

Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xxxxxxxxxx>
---
 Changes in v3:
	1. As Mathias suggested, moved the position of reading devicetree
	   property "imod-interval-ns" into for loop

 Changes in v2:
	1. As suggested by Mathias, restoring immod_interval changes to
	   default
---
 drivers/usb/host/xhci-plat.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index c1b22fc..b5a14ca 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -152,7 +152,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 {
 	const struct xhci_plat_priv *priv_match;
 	const struct hc_driver	*driver;
-	struct device		*sysdev;
+	struct device		*sysdev, *tmpdev;
 	struct xhci_hcd		*xhci;
 	struct resource         *res;
 	struct usb_hcd		*hcd;
@@ -272,19 +272,24 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		goto disable_clk;
 	}
 
-	if (device_property_read_bool(sysdev, "usb2-lpm-disable"))
-		xhci->quirks |= XHCI_HW_LPM_DISABLE;
+	/* imod_interval is the interrupt moderation value in nanoseconds. */
+	xhci->imod_interval = 40000;
 
-	if (device_property_read_bool(sysdev, "usb3-lpm-capable"))
-		xhci->quirks |= XHCI_LPM_SUPPORT;
+	/* Iterate over all parent nodes for finding quirks */
+	for (tmpdev = &pdev->dev; tmpdev; tmpdev = tmpdev->parent) {
 
-	if (device_property_read_bool(&pdev->dev, "quirk-broken-port-ped"))
-		xhci->quirks |= XHCI_BROKEN_PORT_PED;
+		if (device_property_read_bool(tmpdev, "usb2-lpm-disable"))
+			xhci->quirks |= XHCI_HW_LPM_DISABLE;
 
-	/* imod_interval is the interrupt moderation value in nanoseconds. */
-	xhci->imod_interval = 40000;
-	device_property_read_u32(sysdev, "imod-interval-ns",
-				 &xhci->imod_interval);
+		if (device_property_read_bool(tmpdev, "usb3-lpm-capable"))
+			xhci->quirks |= XHCI_LPM_SUPPORT;
+
+		if (device_property_read_bool(tmpdev, "quirk-broken-port-ped"))
+			xhci->quirks |= XHCI_BROKEN_PORT_PED;
+
+		device_property_read_u32(tmpdev, "imod-interval-ns",
+					 &xhci->imod_interval);
+	}
 
 	hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev, "usb-phy", 0);
 	if (IS_ERR(hcd->usb_phy)) {
-- 
2.1.1