Patch "phy: phy-brcm-usb-init: DRD mode can cause crash on startup" has been added to the 4.15-stable tree

Patch "phy: phy-brcm-usb-init: DRD mode can cause crash on startup" has been added to the 4.15-stable tree

[gregkh]

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

    phy: phy-brcm-usb-init: DRD mode can cause crash on startup

to the 4.15-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:
     phy-phy-brcm-usb-init-drd-mode-can-cause-crash-on-startup.patch
and it can be found in the queue-4.15 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 0aa0c12262fd848c48448c39ff6c1c097be00dd4 Mon Sep 17 00:00:00 2001
From: Al Cooper <al.cooper@broadcom.com>
Date: Wed, 27 Dec 2017 14:28:51 -0500
Subject: phy: phy-brcm-usb-init: DRD mode can cause crash on startup

From: Al Cooper <al.cooper@broadcom.com>

commit 0aa0c12262fd848c48448c39ff6c1c097be00dd4 upstream.

This is caused by a bug in the BDC core. When the BDC core comes
out of reset and it's not selected, it gets a backup clock. When
the BDC core is selected, it get's the main clock. If HOST mode
is then selected the BDC core has the main clock shut off but
the backup clock is not restored.

The failure scenario and cause are as follows:
- DRD mode is active
- Device mode is selected first in bootloader
- When host mode is now selected, the clock to the BDC is cut off.
- BDC registers are inaccessible and therefore the BDC driver
  crashes upon Linux boot.

The fix is to have the phy driver always force a BDC reset on
startup.

Fixes: 49859e55e364 ("phy: usb: phy-brcm-usb: Add Broadcom STB USB phy driver")
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/phy/broadcom/phy-brcm-usb-init.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/phy/broadcom/phy-brcm-usb-init.c
+++ b/drivers/phy/broadcom/phy-brcm-usb-init.c
@@ -917,6 +917,7 @@ void brcm_usb_init_common(struct brcm_us
 			USB_CTRL_UNSET_FAMILY(params, USB_PM, BDC_SOFT_RESETB);
 			break;
 		default:
+			USB_CTRL_UNSET_FAMILY(params, USB_PM, BDC_SOFT_RESETB);
 			USB_CTRL_SET_FAMILY(params, USB_PM, BDC_SOFT_RESETB);
 		break;
 		}


Patches currently in stable-queue which might be from al.cooper@broadcom.com are

queue-4.15/phy-phy-brcm-usb-init-power-down-usb-3.0-phy-when-xhci-disabled.patch
queue-4.15/phy-phy-brcm-usb-init-drd-mode-can-cause-crash-on-startup.patch
queue-4.15/phy-phy-brcm-usb-init-some-low-speed-keyboards-fail-on-7271.patch