From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752600AbdL0T3x (ORCPT ); Wed, 27 Dec 2017 14:29:53 -0500 Received: from rnd-relay.smtp.broadcom.com ([192.19.229.170]:58270 "EHLO rnd-relay.smtp.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752441AbdL0T3v (ORCPT ); Wed, 27 Dec 2017 14:29:51 -0500 From: Al Cooper To: Kishon Vijay Abraham I Cc: Al Cooper , Al Cooper , linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com Subject: [PATCH 4/4] phy: usb: phy-brcm-usb-init: DRD mode can cause crash on startup Date: Wed, 27 Dec 2017 14:28:51 -0500 Message-Id: <1514402931-14408-5-git-send-email-alcooperx@gmail.com> X-Mailer: git-send-email 1.9.0.138.g2de3478 In-Reply-To: <1514402931-14408-1-git-send-email-alcooperx@gmail.com> References: <1514402931-14408-1-git-send-email-alcooperx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Cooper 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 --- drivers/phy/broadcom/phy-brcm-usb-init.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/phy/broadcom/phy-brcm-usb-init.c b/drivers/phy/broadcom/phy-brcm-usb-init.c index 6672adcc..1b7febc 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; } -- 1.9.0.138.g2de3478