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

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 <[email protected]> know about it.

From: Al Cooper <[email protected]>
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 <[email protected]>

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.

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

@@ -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 [email protected] 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