From: Al Cooper Date: Wed, 27 Dec 2017 19:28:51 +0000 (-0500) Subject: phy: phy-brcm-usb-init: DRD mode can cause crash on startup X-Git-Tag: v4.15.12~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5fb7cf9b1ca0fa06cc63a514bf639529fbd95d49;p=thirdparty%2Fkernel%2Fstable.git phy: phy-brcm-usb-init: DRD mode can cause crash on startup 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 Acked-by: Florian Fainelli Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/phy/broadcom/phy-brcm-usb-init.c b/drivers/phy/broadcom/phy-brcm-usb-init.c index 69ea47945292a..4890cade650ef 100644 --- 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_usb_init_params *params) 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; }