From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965085AbbJ1IBF (ORCPT ); Wed, 28 Oct 2015 04:01:05 -0400 Received: from mga11.intel.com ([192.55.52.93]:12818 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965024AbbJ1IBB (ORCPT ); Wed, 28 Oct 2015 04:01:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,209,1444719600"; d="scan'208";a="673345997" From: Lu Baolu To: Mathias Nyman , Greg Kroah-Hartman , Alan Stern Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 07/12] usb: xhci: dbc: handle dbc-configured exit Date: Wed, 28 Oct 2015 16:00:38 +0800 Message-Id: <1446019243-5565-8-git-send-email-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1446019243-5565-1-git-send-email-baolu.lu@linux.intel.com> References: <1446019243-5565-1-git-send-email-baolu.lu@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org DbC might exit configured state in some cases (refer to 7.6.4.4 in xHCI spec 1.1). Software needs detect and clear this situation by clearing DCCTRL.DCR and wait until the DbC configured before read or write oprations. Signed-off-by: Lu Baolu --- drivers/usb/early/xhci-dbc.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index f51daa4..8a5a51f 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -1153,6 +1153,29 @@ static int xdbc_wait_until_bulk_done(struct xdbc_trb *trb, int loops) return -EIO; } +static int xdbc_wait_until_dbc_configured(void) +{ + int timeout = 0; + u32 reg; + + /* Port exits configured state */ + reg = readl(&xdbcp->xdbc_reg->control); + if (!(reg & CTRL_DRC)) + return 0; + + /* clear run change bit (RW1C) */ + writel(reg | CTRL_DRC, &xdbcp->xdbc_reg->control); + + do { + if (readl(&xdbcp->xdbc_reg->control) & CTRL_DCR) + return 0; + + xdbc_udelay(10); + } while (timeout++ < XDBC_LOOPS); + + return -ETIMEDOUT; +} + static int xdbc_bulk_transfer(void *data, int size, int loops, bool read) { u64 addr; @@ -1167,6 +1190,11 @@ static int xdbc_bulk_transfer(void *data, int size, int loops, bool read) return -EINVAL; } + if (xdbc_wait_until_dbc_configured()) { + xdbc_trace("%s: hardware not ready\n", __func__); + return -EPERM; + } + ring = (read ? &xdbcp->in_ring : &xdbcp->out_ring); trb = ring->enqueue; cycle = ring->cycle_state; -- 2.1.4