Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755967AbYCQRhA (ORCPT ); Mon, 17 Mar 2008 13:37:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755555AbYCQRgu (ORCPT ); Mon, 17 Mar 2008 13:36:50 -0400 Received: from outbound-sin.frontbridge.com ([207.46.51.80]:4276 "EHLO outbound9-sin-R.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755204AbYCQRgt (ORCPT ); Mon, 17 Mar 2008 13:36:49 -0400 X-BigFish: VP X-MS-Exchange-Organization-Antispam-Report: OrigIP: 149.199.60.83;Service: EHS From: Stephen Neuendorffer To: grant.likely@secretlab.ca, git-dev@xilinx.com, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Cc: Stephen Neuendorffer Subject: [PATCH 2/3] Xilinx: hwicap: Verify sync before reading idcode. Date: Mon, 17 Mar 2008 10:36:31 -0700 X-Mailer: git-send-email 1.5.3.4-dirty In-Reply-To: <1205775392-32222-2-git-send-email-stephen.neuendorffer@xilinx.com> References: <1205775392-32222-1-git-send-email-stephen.neuendorffer@xilinx.com> <1205775392-32222-2-git-send-email-stephen.neuendorffer@xilinx.com> Message-Id: <20080317173645.7A21D9A8069@mail131-sin.bigfish.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2124 Lines: 55 It appears that in some cases, the sync word might not be recognized by the hardware correctly. If this happens, then attempting to read from the port results in an unrecoverable error because of the design of the FPGA core. This patch updates the code to check the status of the device before reading the IDCODE, in order to avoid entering this unrecoverable state. This patch also adds additional NOOP commands into the sychronization sequence, which appears to be necessary to avoid the condition on some hardware. Signed-off-by: Stephen Neuendorffer --- drivers/char/xilinx_hwicap/xilinx_hwicap.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.c b/drivers/char/xilinx_hwicap/xilinx_hwicap.c index 304727d..5b8d646 100644 --- a/drivers/char/xilinx_hwicap/xilinx_hwicap.c +++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.c @@ -250,8 +250,26 @@ static int hwicap_get_configuration_register(struct hwicap_drvdata *drvdata, * Create the data to be written to the ICAP. */ buffer[index++] = XHI_DUMMY_PACKET; + buffer[index++] = XHI_NOOP_PACKET; buffer[index++] = XHI_SYNC_PACKET; buffer[index++] = XHI_NOOP_PACKET; + buffer[index++] = XHI_NOOP_PACKET; + + /* + * Write the data to the FIFO and initiate the transfer of data present + * in the FIFO to the ICAP device. + */ + status = drvdata->config->set_configuration(drvdata, + &buffer[0], index); + if (status) + return status; + + /* If the syncword was not found, then we need to start over. */ + status = drvdata->config->get_status(drvdata); + if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK) + return -EIO; + + index = 0; buffer[index++] = hwicap_type_1_read(reg) | 1; buffer[index++] = XHI_NOOP_PACKET; buffer[index++] = XHI_NOOP_PACKET; -- 1.5.3.4-dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/