From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965811AbcAZM7P (ORCPT ); Tue, 26 Jan 2016 07:59:15 -0500 Received: from mga02.intel.com ([134.134.136.20]:47679 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965212AbcAZM6l (ORCPT ); Tue, 26 Jan 2016 07:58:41 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,350,1449561600"; d="scan'208";a="898535779" From: Lu Baolu To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v7 06/10] usb: dbc: handle dbc-configured exit Date: Tue, 26 Jan 2016 20:58:12 +0800 Message-Id: <1453813096-6991-7-git-send-email-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1453813096-6991-1-git-send-email-baolu.lu@linux.intel.com> References: <1453813096-6991-1-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 f59c80ef..c81df40 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -1140,6 +1140,29 @@ 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; @@ -1154,6 +1177,11 @@ 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