From patchwork Tue Mar 6 01:55:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Poirier X-Patchwork-Id: 881850 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zwKdW07hWz9sb6 for ; Tue, 6 Mar 2018 12:56:47 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932228AbeCFB4S (ORCPT ); Mon, 5 Mar 2018 20:56:18 -0500 Received: from mx2.suse.de ([195.135.220.15]:58090 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752017AbeCFB4R (ORCPT ); Mon, 5 Mar 2018 20:56:17 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 1E55DAE20; Tue, 6 Mar 2018 01:56:15 +0000 (UTC) From: Benjamin Poirier To: Jeff Kirsher Cc: Alexander Duyck , Lennart Sorensen , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] Revert "e1000e: Separate signaling for link check/link up" Date: Tue, 6 Mar 2018 10:55:52 +0900 Message-Id: <20180306015553.10441-1-bpoirier@suse.com> X-Mailer: git-send-email 2.16.2 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This reverts commit 19110cfbb34d4af0cdfe14cd243f3b09dc95b013. This reverts commit 4110e02eb45ea447ec6f5459c9934de0a273fb91. This reverts commit d3604515c9eda464a92e8e67aae82dfe07fe3c98. Commit 19110cfbb34d ("e1000e: Separate signaling for link check/link up") changed what happens to the link status when there is an error which happens after "get_link_status = false" in the copper check_for_link callbacks. Previously, such an error would be ignored and the link considered up. After that commit, any error implies that the link is down. Revert commit 19110cfbb34d ("e1000e: Separate signaling for link check/link up") and its followups. After reverting, the race condition described in the log of commit 19110cfbb34d is reintroduced. It may still be triggered by LSC events but this should keep the link down in case the link is electrically unstable, as discussed. The race may no longer be triggered by RXO events because commit 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts") restored reading icr in the Other handler. Link: https://lkml.org/lkml/2018/3/1/789 Signed-off-by: Benjamin Poirier Acked-by: Alexander Duyck Tested-by: Aaron Brown --- drivers/net/ethernet/intel/e1000e/ich8lan.c | 13 ++++--------- drivers/net/ethernet/intel/e1000e/mac.c | 13 ++++--------- drivers/net/ethernet/intel/e1000e/netdev.c | 2 +- 3 files changed, 9 insertions(+), 19 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c index ff308b05d68c..d6d4ed7acf03 100644 --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c @@ -1367,9 +1367,6 @@ static s32 e1000_disable_ulp_lpt_lp(struct e1000_hw *hw, bool force) * Checks to see of the link status of the hardware has changed. If a * change in link status has been detected, then we read the PHY registers * to get the current speed/duplex if link exists. - * - * Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link - * up). **/ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) { @@ -1385,7 +1382,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) * Change or Rx Sequence Error interrupt. */ if (!mac->get_link_status) - return 1; + return 0; /* First we want to see if the MII Status Register reports * link. If so, then we want to get the current speed/duplex @@ -1602,7 +1599,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) * we have already determined whether we have link or not. */ if (!mac->autoneg) - return 1; + return -E1000_ERR_CONFIG; /* Auto-Neg is enabled. Auto Speed Detection takes care * of MAC speed/duplex configuration. So we only need to @@ -1616,12 +1613,10 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) * different link partner. */ ret_val = e1000e_config_fc_after_link_up(hw); - if (ret_val) { + if (ret_val) e_dbg("Error configuring flow control\n"); - return ret_val; - } - return 1; + return ret_val; } static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter) diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c index db735644b312..b322011ec282 100644 --- a/drivers/net/ethernet/intel/e1000e/mac.c +++ b/drivers/net/ethernet/intel/e1000e/mac.c @@ -410,9 +410,6 @@ void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw) * Checks to see of the link status of the hardware has changed. If a * change in link status has been detected, then we read the PHY registers * to get the current speed/duplex if link exists. - * - * Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link - * up). **/ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) { @@ -426,7 +423,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) * Change or Rx Sequence Error interrupt. */ if (!mac->get_link_status) - return 1; + return 0; /* First we want to see if the MII Status Register reports * link. If so, then we want to get the current speed/duplex @@ -450,7 +447,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) * we have already determined whether we have link or not. */ if (!mac->autoneg) - return 1; + return -E1000_ERR_CONFIG; /* Auto-Neg is enabled. Auto Speed Detection takes care * of MAC speed/duplex configuration. So we only need to @@ -464,12 +461,10 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) * different link partner. */ ret_val = e1000e_config_fc_after_link_up(hw); - if (ret_val) { + if (ret_val) e_dbg("Error configuring flow control\n"); - return ret_val; - } - return 1; + return ret_val; } /** diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 9fd4050a91ca..8a3aa85b159c 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5090,7 +5090,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter) case e1000_media_type_copper: if (hw->mac.get_link_status) { ret_val = hw->mac.ops.check_for_link(hw); - link_active = ret_val > 0; + link_active = !hw->mac.get_link_status; } else { link_active = true; } From patchwork Tue Mar 6 01:55:53 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Poirier X-Patchwork-Id: 881849 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zwKdN3vHqz9sb9 for ; Tue, 6 Mar 2018 12:56:40 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932446AbeCFB41 (ORCPT ); Mon, 5 Mar 2018 20:56:27 -0500 Received: from mx2.suse.de ([195.135.220.15]:58107 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932406AbeCFB4Z (ORCPT ); Mon, 5 Mar 2018 20:56:25 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 0EBEFAF80; Tue, 6 Mar 2018 01:56:24 +0000 (UTC) From: Benjamin Poirier To: Jeff Kirsher Cc: Alexander Duyck , Lennart Sorensen , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] e1000e: Fix link check race condition Date: Tue, 6 Mar 2018 10:55:53 +0900 Message-Id: <20180306015553.10441-2-bpoirier@suse.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180306015553.10441-1-bpoirier@suse.com> References: <20180306015553.10441-1-bpoirier@suse.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Alex reported the following race condition: /* link goes up... interrupt... schedule watchdog */ \ e1000_watchdog_task \ e1000e_has_link \ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link \ e1000e_phy_has_link_generic(..., &link) link = true /* link goes down... interrupt */ \ e1000_msix_other hw->mac.get_link_status = true /* link is up */ mac->get_link_status = false link_active = true /* link_active is true, wrongly, and stays so because * get_link_status is false */ Avoid this problem by making sure that we don't set get_link_status = false after having checked the link. It seems this problem has been present since the introduction of e1000e. Link: https://lkml.org/lkml/2018/1/29/338 Reported-by: Alexander Duyck Signed-off-by: Benjamin Poirier Acked-by: Alexander Duyck Tested-by: Aaron Brown --- drivers/net/ethernet/intel/e1000e/ich8lan.c | 31 ++++++++++++++++------------- drivers/net/ethernet/intel/e1000e/mac.c | 14 ++++++------- 2 files changed, 24 insertions(+), 21 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c index d6d4ed7acf03..1dddfb7b2de6 100644 --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c @@ -1383,6 +1383,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) */ if (!mac->get_link_status) return 0; + mac->get_link_status = false; /* First we want to see if the MII Status Register reports * link. If so, then we want to get the current speed/duplex @@ -1390,12 +1391,12 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) */ ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link); if (ret_val) - return ret_val; + goto out; if (hw->mac.type == e1000_pchlan) { ret_val = e1000_k1_gig_workaround_hv(hw, link); if (ret_val) - return ret_val; + goto out; } /* When connected at 10Mbps half-duplex, some parts are excessively @@ -1428,7 +1429,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) ret_val = hw->phy.ops.acquire(hw); if (ret_val) - return ret_val; + goto out; if (hw->mac.type == e1000_pch2lan) emi_addr = I82579_RX_CONFIG; @@ -1450,7 +1451,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) hw->phy.ops.release(hw); if (ret_val) - return ret_val; + goto out; if (hw->mac.type >= e1000_pch_spt) { u16 data; @@ -1459,14 +1460,14 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) if (speed == SPEED_1000) { ret_val = hw->phy.ops.acquire(hw); if (ret_val) - return ret_val; + goto out; ret_val = e1e_rphy_locked(hw, PHY_REG(776, 20), &data); if (ret_val) { hw->phy.ops.release(hw); - return ret_val; + goto out; } ptr_gap = (data & (0x3FF << 2)) >> 2; @@ -1480,18 +1481,18 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) } hw->phy.ops.release(hw); if (ret_val) - return ret_val; + goto out; } else { ret_val = hw->phy.ops.acquire(hw); if (ret_val) - return ret_val; + goto out; ret_val = e1e_wphy_locked(hw, PHY_REG(776, 20), 0xC023); hw->phy.ops.release(hw); if (ret_val) - return ret_val; + goto out; } } @@ -1518,7 +1519,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) (hw->adapter->pdev->device == E1000_DEV_ID_PCH_I218_V3)) { ret_val = e1000_k1_workaround_lpt_lp(hw, link); if (ret_val) - return ret_val; + goto out; } if (hw->mac.type >= e1000_pch_lpt) { /* Set platform power management values for @@ -1526,7 +1527,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) */ ret_val = e1000_platform_pm_pch_lpt(hw, link); if (ret_val) - return ret_val; + goto out; } /* Clear link partner's EEE ability */ @@ -1549,9 +1550,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) } if (!link) - return 0; /* No link detected */ - - mac->get_link_status = false; + goto out; switch (hw->mac.type) { case e1000_pch2lan: @@ -1617,6 +1616,10 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) e_dbg("Error configuring flow control\n"); return ret_val; + +out: + mac->get_link_status = true; + return ret_val; } static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter) diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c index b322011ec282..5bdc3a2d4fd7 100644 --- a/drivers/net/ethernet/intel/e1000e/mac.c +++ b/drivers/net/ethernet/intel/e1000e/mac.c @@ -424,19 +424,15 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) */ if (!mac->get_link_status) return 0; + mac->get_link_status = false; /* First we want to see if the MII Status Register reports * link. If so, then we want to get the current speed/duplex * of the PHY. */ ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link); - if (ret_val) - return ret_val; - - if (!link) - return 0; /* No link detected */ - - mac->get_link_status = false; + if (ret_val || !link) + goto out; /* Check if there was DownShift, must be checked * immediately after link-up @@ -465,6 +461,10 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) e_dbg("Error configuring flow control\n"); return ret_val; + +out: + mac->get_link_status = true; + return ret_val; } /**