Patch "usb: host: xhci: add a new quirk XHCI_NO_64BIT_SUPPORT" has been added to the 4.5-stable tree

[<gregkh@linuxfoundation.org>]

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

    usb: host: xhci: add a new quirk XHCI_NO_64BIT_SUPPORT

to the 4.5-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-add-a-new-quirk-xhci_no_64bit_support.patch
and it can be found in the queue-4.5 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 0a380be8233dbf8dd20795b801c5d5d5ef3992f7 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Fri, 8 Apr 2016 16:25:07 +0300
Subject: usb: host: xhci: add a new quirk XHCI_NO_64BIT_SUPPORT

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

commit 0a380be8233dbf8dd20795b801c5d5d5ef3992f7 upstream.

On some xHCI controllers (e.g. R-Car SoCs), the AC64 bit (bit 0) of
HCCPARAMS1 is set to 1. However, the xHCs don't support 64-bit
address memory pointers actually. So, in this case, this driver should
call dma_set_coherent_mask(dev, DMA_BIT_MASK(32)) in xhci_gen_setup().
Otherwise, the xHCI controller will be died after a usb device is
connected if it runs on above 4GB physical memory environment.

So, this patch adds a new quirk XHCI_NO_64BIT_SUPPORT to resolve
such an issue.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/host/xhci.c |   10 ++++++++++
 drivers/usb/host/xhci.h |    1 +
 2 files changed, 11 insertions(+)

--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4944,6 +4944,16 @@ int xhci_gen_setup(struct usb_hcd *hcd,
 		return retval;
 	xhci_dbg(xhci, "Reset complete\n");
 
+	/*
+	 * On some xHCI controllers (e.g. R-Car SoCs), the AC64 bit (bit 0)
+	 * of HCCPARAMS1 is set to 1. However, the xHCs don't support 64-bit
+	 * address memory pointers actually. So, this driver clears the AC64
+	 * bit of xhci->hcc_params to call dma_set_coherent_mask(dev,
+	 * DMA_BIT_MASK(32)) in this xhci_gen_setup().
+	 */
+	if (xhci->quirks & XHCI_NO_64BIT_SUPPORT)
+		xhci->hcc_params &= ~BIT(0);
+
 	/* Set dma_mask and coherent_dma_mask to 64-bits,
 	 * if xHC supports 64-bit addressing */
 	if (HCC_64BIT_ADDR(xhci->hcc_params) &&
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1632,6 +1632,7 @@ struct xhci_hcd {
 #define XHCI_PME_STUCK_QUIRK	(1 << 20)
 #define XHCI_MTK_HOST		(1 << 21)
 #define XHCI_SSIC_PORT_UNUSED	(1 << 22)
+#define XHCI_NO_64BIT_SUPPORT	(1 << 23)
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
 	/* There are two roothubs to keep track of bus suspend info for */


Patches currently in stable-queue which might be from yoshihiro.shimoda.uh@renesas.com are

queue-4.5/usb-host-xhci-plat-make-enum-xhci_plat_type-start-at-a-non-zero-value.patch
queue-4.5/usb-host-xhci-plat-fix-cannot-work-if-r-car-gen2-3-run-on-above-4gb-phys.patch
queue-4.5/usb-host-xhci-add-a-new-quirk-xhci_no_64bit_support.patch