Patch "usb: host: xhci-plat: allow sysdev to inherit from ACPI" has been added to the 4.13-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    usb: host: xhci-plat: allow sysdev to inherit from ACPI

to the 4.13-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-host-xhci-plat-allow-sysdev-to-inherit-from-acpi.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From c6b8e79306f515b5483eb11076e0fbfc140434a8 Mon Sep 17 00:00:00 2001
From: Adam Wallis <awallis@codeaurora.org>
Date: Mon, 18 Sep 2017 17:39:16 +0300
Subject: usb: host: xhci-plat: allow sysdev to inherit from ACPI

From: Adam Wallis <awallis@codeaurora.org>

commit c6b8e79306f515b5483eb11076e0fbfc140434a8 upstream.

Commit 4c39d4b949d3 ("usb: xhci: use bus->sysdev for DMA configuration")
updated the method determining DMA for XHCI from sysdev. However, this
patch broke the ability to enumerate the FWNODE from parent ACPI devices
from the child plat XHCI device.

Currently, xhci_plat is not set up properly when the parent device is an
ACPI node. The conditions that xhci_plat_probe should satisfy are

1. xhci_plat comes from firmware
2. xhci_plat is child of a device from firmware (dwc3-plat)
3. xhci_plat is grandchild of a pci device (dwc3-pci)

Case 2 is covered when the child is an OF node (by checking
sysdev->parent->of_node), however, an ACPI parent will return NULL in
the of_node check and will thus not result in sysdev being set to
sysdev->parent

[   17.591549] xhci-hcd: probe of xhci-hcd.6.auto failed with error -5

This change adds a check for ACPI to completely allow for condition 2.
This is done by first checking if the parent node is of type ACPI (e.g.,
dwc3-plat) and set sysdev to sysdev->parent if either of the two
following conditions are met:

1: If fwnode is empty (in the case that platform_device_add_properties
was not called on the allocated platform device)
2: fwnode exists but is not of type ACPI (this would happen if
platform_device_add_properties was called on the allocated device.
Instead of type FWNODE_ACPI, you would end up with FWNODE_PDATA)

Fixes: 4c39d4b949d3 ("usb: xhci: use bus->sysdev for DMA configuration")
Tested-by: Thang Q. Nguyen <tqnguyen@apm.com>
Signed-off-by: Adam Wallis <awallis@codeaurora.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/host/xhci-plat.c |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -186,14 +186,18 @@ static int xhci_plat_probe(struct platfo
 	 * 2. xhci_plat is child of a device from firmware (dwc3-plat)
 	 * 3. xhci_plat is grandchild of a pci device (dwc3-pci)
 	 */
-	sysdev = &pdev->dev;
-	if (sysdev->parent && !sysdev->of_node && sysdev->parent->of_node)
-		sysdev = sysdev->parent;
+	for (sysdev = &pdev->dev; sysdev; sysdev = sysdev->parent) {
+		if (is_of_node(sysdev->fwnode) ||
+			is_acpi_device_node(sysdev->fwnode))
+			break;
 #ifdef CONFIG_PCI
-	else if (sysdev->parent && sysdev->parent->parent &&
-		 sysdev->parent->parent->bus == &pci_bus_type)
-		sysdev = sysdev->parent->parent;
+		else if (sysdev->bus == &pci_bus_type)
+			break;
 #endif
+	}
+
+	if (!sysdev)
+		sysdev = &pdev->dev;
 
 	/* Try to set 64-bit DMA first */
 	if (WARN_ON(!sysdev->dma_mask))


Patches currently in stable-queue which might be from awallis@codeaurora.org are

queue-4.13/usb-host-xhci-plat-allow-sysdev-to-inherit-from-acpi.patch