From 0aa0c12262fd848c48448c39ff6c1c097be00dd4 Mon Sep 17 00:00:00 2001 From: Al Cooper Date: Wed, 27 Dec 2017 14:28:51 -0500 Subject: phy: phy-brcm-usb-init: DRD mode can cause crash on startup 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 --- drivers/phy/broadcom/phy-brcm-usb-init.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/phy/broadcom') diff --git a/drivers/phy/broadcom/phy-brcm-usb-init.c b/drivers/phy/broadcom/phy-brcm-usb-init.c index 6672adcc5894..1b7febc43da9 100644 --- a/drivers/phy/broadcom/phy-brcm-usb-init.c +++ b/drivers/phy/broadcom/phy-brcm-usb-init.c @@ -918,6 +918,7 @@ 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; } -- cgit v1.2.3-59-g8ed1b