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GET /api/patches/792262/?format=api
HTTP 200 OK
Allow: GET, PUT, PATCH, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "id": 792262,
    "url": "http://patchwork.ozlabs.org/api/patches/792262/?format=api",
    "web_url": "http://patchwork.ozlabs.org/project/intel-wired-lan/patch/20170721183627.13373-4-bpoirier@suse.com/",
    "project": {
        "id": 46,
        "url": "http://patchwork.ozlabs.org/api/projects/46/?format=api",
        "name": "Intel Wired Ethernet development",
        "link_name": "intel-wired-lan",
        "list_id": "intel-wired-lan.osuosl.org",
        "list_email": "intel-wired-lan@osuosl.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": "",
        "list_archive_url": "",
        "list_archive_url_format": "",
        "commit_url_format": ""
    },
    "msgid": "<20170721183627.13373-4-bpoirier@suse.com>",
    "list_archive_url": null,
    "date": "2017-07-21T18:36:26",
    "name": "[4/5] e1000e: Separate signaling for link check/link up",
    "commit_ref": null,
    "pull_url": null,
    "state": "accepted",
    "archived": false,
    "hash": "73d8c938b35b25826fe58e6a13e6ad9aa9528008",
    "submitter": {
        "id": 67008,
        "url": "http://patchwork.ozlabs.org/api/people/67008/?format=api",
        "name": "Benjamin Poirier",
        "email": "bpoirier@suse.com"
    },
    "delegate": {
        "id": 68,
        "url": "http://patchwork.ozlabs.org/api/users/68/?format=api",
        "username": "jtkirshe",
        "first_name": "Jeff",
        "last_name": "Kirsher",
        "email": "jeffrey.t.kirsher@intel.com"
    },
    "mbox": "http://patchwork.ozlabs.org/project/intel-wired-lan/patch/20170721183627.13373-4-bpoirier@suse.com/mbox/",
    "series": [],
    "comments": "http://patchwork.ozlabs.org/api/patches/792262/comments/",
    "check": "pending",
    "checks": "http://patchwork.ozlabs.org/api/patches/792262/checks/",
    "tags": {},
    "related": [],
    "headers": {
        "Return-Path": "<intel-wired-lan-bounces@osuosl.org>",
        "X-Original-To": [
            "incoming@patchwork.ozlabs.org",
            "intel-wired-lan@lists.osuosl.org"
        ],
        "Delivered-To": [
            "patchwork-incoming@bilbo.ozlabs.org",
            "intel-wired-lan@lists.osuosl.org"
        ],
        "Authentication-Results": "ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=osuosl.org\n\t(client-ip=140.211.166.136; helo=silver.osuosl.org;\n\tenvelope-from=intel-wired-lan-bounces@osuosl.org;\n\treceiver=<UNKNOWN>)",
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            "from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xDfdB5zXDz9rvt\n\tfor <incoming@patchwork.ozlabs.org>;\n\tSat, 22 Jul 2017 04:37:18 +1000 (AEST)",
            "from localhost (localhost [127.0.0.1])\n\tby silver.osuosl.org (Postfix) with ESMTP id DC6762F6A1;\n\tFri, 21 Jul 2017 18:37:16 +0000 (UTC)",
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            "from ash.osuosl.org (ash.osuosl.org [140.211.166.34])\n\tby silver.osuosl.org (Postfix) with ESMTP id DE20E2F65B;\n\tFri, 21 Jul 2017 18:37:14 +0000 (UTC)",
            "from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138])\n\tby ash.osuosl.org (Postfix) with ESMTP id CBFD71C0964\n\tfor <intel-wired-lan@lists.osuosl.org>;\n\tFri, 21 Jul 2017 18:37:12 +0000 (UTC)",
            "from localhost (localhost [127.0.0.1])\n\tby whitealder.osuosl.org (Postfix) with ESMTP id CC82B88B3F\n\tfor <intel-wired-lan@lists.osuosl.org>;\n\tFri, 21 Jul 2017 18:36:58 +0000 (UTC)",
            "from whitealder.osuosl.org ([127.0.0.1])\n\tby localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024)\n\twith ESMTP id qqQaqVVQsBoe for <intel-wired-lan@lists.osuosl.org>;\n\tFri, 21 Jul 2017 18:36:58 +0000 (UTC)",
            "from mx1.suse.de (mx2.suse.de [195.135.220.15])\n\tby whitealder.osuosl.org (Postfix) with ESMTPS id EB0DA88991\n\tfor <intel-wired-lan@lists.osuosl.org>;\n\tFri, 21 Jul 2017 18:36:57 +0000 (UTC)",
            "from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254])\n\tby mx1.suse.de (Postfix) with ESMTP id 6EDC7AC03;\n\tFri, 21 Jul 2017 18:36:56 +0000 (UTC)"
        ],
        "X-Virus-Scanned": [
            "amavisd-new at osuosl.org",
            "amavisd-new at osuosl.org",
            "by amavisd-new at test-mx.suse.de"
        ],
        "X-Greylist": "domain auto-whitelisted by SQLgrey-1.7.6",
        "From": "Benjamin Poirier <bpoirier@suse.com>",
        "To": "Jeff Kirsher <jeffrey.t.kirsher@intel.com>",
        "Date": "Fri, 21 Jul 2017 11:36:26 -0700",
        "Message-Id": "<20170721183627.13373-4-bpoirier@suse.com>",
        "X-Mailer": "git-send-email 2.13.2",
        "In-Reply-To": "<20170721183627.13373-1-bpoirier@suse.com>",
        "References": "<20170721160937.GA22632@csclub.uwaterloo.ca>\n\t<20170721183627.13373-1-bpoirier@suse.com>",
        "Cc": "netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org,\n\tlinux-kernel@vger.kernel.org,\n\tLennart Sorensen <lsorense@csclub.uwaterloo.ca>",
        "Subject": "[Intel-wired-lan] [PATCH 4/5] e1000e: Separate signaling for link\n\tcheck/link up",
        "X-BeenThere": "intel-wired-lan@osuosl.org",
        "X-Mailman-Version": "2.1.18-1",
        "Precedence": "list",
        "List-Id": "Intel Wired Ethernet Linux Kernel Driver Development\n\t<intel-wired-lan.osuosl.org>",
        "List-Unsubscribe": "<https://lists.osuosl.org/mailman/options/intel-wired-lan>, \n\t<mailto:intel-wired-lan-request@osuosl.org?subject=unsubscribe>",
        "List-Archive": "<http://lists.osuosl.org/pipermail/intel-wired-lan/>",
        "List-Post": "<mailto:intel-wired-lan@osuosl.org>",
        "List-Help": "<mailto:intel-wired-lan-request@osuosl.org?subject=help>",
        "List-Subscribe": "<https://lists.osuosl.org/mailman/listinfo/intel-wired-lan>, \n\t<mailto:intel-wired-lan-request@osuosl.org?subject=subscribe>",
        "MIME-Version": "1.0",
        "Content-Type": "text/plain; charset=\"us-ascii\"",
        "Content-Transfer-Encoding": "7bit",
        "Errors-To": "intel-wired-lan-bounces@osuosl.org",
        "Sender": "\"Intel-wired-lan\" <intel-wired-lan-bounces@osuosl.org>"
    },
    "content": "Lennart reported the following race condition:\n\n\\ e1000_watchdog_task\n    \\ e1000e_has_link\n        \\ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link\n            /* link is up */\n            mac->get_link_status = false;\n\n                            /* interrupt */\n                            \\ e1000_msix_other\n                                hw->mac.get_link_status = true;\n\n        link_active = !hw->mac.get_link_status\n        /* link_active is false, wrongly */\n\nThis problem arises because the single flag get_link_status is used to\nsignal two different states: link status needs checking and link status is\ndown.\n\nAvoid the problem by using the return value of .check_for_link to signal\nthe link status to e1000e_has_link().\n\nReported-by: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>\nSigned-off-by: Benjamin Poirier <bpoirier@suse.com>\n---\n drivers/net/ethernet/intel/e1000e/mac.c    | 11 ++++++++---\n drivers/net/ethernet/intel/e1000e/netdev.c |  2 +-\n 2 files changed, 9 insertions(+), 4 deletions(-)",
    "diff": "diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c\nindex b322011ec282..f457c5703d0c 100644\n--- a/drivers/net/ethernet/intel/e1000e/mac.c\n+++ b/drivers/net/ethernet/intel/e1000e/mac.c\n@@ -410,6 +410,9 @@ void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)\n  *  Checks to see of the link status of the hardware has changed.  If a\n  *  change in link status has been detected, then we read the PHY registers\n  *  to get the current speed/duplex if link exists.\n+ *\n+ *  Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link\n+ *  up).\n  **/\n s32 e1000e_check_for_copper_link(struct e1000_hw *hw)\n {\n@@ -423,7 +426,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)\n \t * Change or Rx Sequence Error interrupt.\n \t */\n \tif (!mac->get_link_status)\n-\t\treturn 0;\n+\t\treturn 1;\n \n \t/* First we want to see if the MII Status Register reports\n \t * link.  If so, then we want to get the current speed/duplex\n@@ -461,10 +464,12 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)\n \t * different link partner.\n \t */\n \tret_val = e1000e_config_fc_after_link_up(hw);\n-\tif (ret_val)\n+\tif (ret_val) {\n \t\te_dbg(\"Error configuring flow control\\n\");\n+\t\treturn ret_val;\n+\t}\n \n-\treturn ret_val;\n+\treturn 1;\n }\n \n /**\ndiff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c\nindex fc6a1d9999b2..5a8ab1136566 100644\n--- a/drivers/net/ethernet/intel/e1000e/netdev.c\n+++ b/drivers/net/ethernet/intel/e1000e/netdev.c\n@@ -5081,7 +5081,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter)\n \tcase e1000_media_type_copper:\n \t\tif (hw->mac.get_link_status) {\n \t\t\tret_val = hw->mac.ops.check_for_link(hw);\n-\t\t\tlink_active = !hw->mac.get_link_status;\n+\t\t\tlink_active = ret_val > 0;\n \t\t} else {\n \t\t\tlink_active = true;\n \t\t}\n",
    "prefixes": [
        "4/5"
    ]
}