From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753246AbbKQGmp (ORCPT ); Tue, 17 Nov 2015 01:42:45 -0500 Received: from mga03.intel.com ([134.134.136.65]:47411 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752146AbbKQGju (ORCPT ); Tue, 17 Nov 2015 01:39:50 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,306,1444719600"; d="scan'208";a="601616820" From: Lu Baolu To: Mathias Nyman , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v4 07/12] usb: xhci: dbc: handle dbc-configured exit Date: Tue, 17 Nov 2015 14:38:53 +0800 Message-Id: <1447742338-8381-8-git-send-email-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1447742338-8381-1-git-send-email-baolu.lu@linux.intel.com> References: <1447742338-8381-1-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