From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EC74C43465 for ; Fri, 18 Sep 2020 02:12:16 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 342BD235F8 for ; Fri, 18 Sep 2020 02:12:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Nr8g0vBv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 342BD235F8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4Bsy5R4pkyzDqVQ for ; Fri, 18 Sep 2020 12:12:11 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=sashal@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=Nr8g0vBv; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Bsxv86n6yzDqf6 for ; Fri, 18 Sep 2020 12:03:16 +1000 (AEST) Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EAF6922211; Fri, 18 Sep 2020 02:03:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600394594; bh=40VmAwP/yTt5HZ9+MDjxbKXNx1hzfy9nGDD8SwFa9Rk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nr8g0vBvCtw6Ify32wRCZaMx0TEsXRRxhQeOmeI11Nw274sRL5AC2ofQ2qNGfGHVF xryQn0ZzZxS3ogF/IgtEvd8deYA8mE2ZAhw+n6J1XLKh5izGMdcovt2gdjdSx3lDLL l5hlrHUV929DWGaJo0XvInFJvYoZsAhU4+R7ex+s= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 102/330] powerpc/eeh: Only dump stack once if an MMIO loop is detected Date: Thu, 17 Sep 2020 21:57:22 -0400 Message-Id: <20200918020110.2063155-102-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200918020110.2063155-1-sashal@kernel.org> References: <20200918020110.2063155-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sam Bobroff , Oliver O'Halloran , linuxppc-dev@lists.ozlabs.org, Sasha Levin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Oliver O'Halloran [ Upstream commit 4e0942c0302b5ad76b228b1a7b8c09f658a1d58a ] Many drivers don't check for errors when they get a 0xFFs response from an MMIO load. As a result after an EEH event occurs a driver can get stuck in a polling loop unless it some kind of internal timeout logic. Currently EEH tries to detect and report stuck drivers by dumping a stack trace after eeh_dev_check_failure() is called EEH_MAX_FAILS times on an already frozen PE. The value of EEH_MAX_FAILS was chosen so that a dump would occur every few seconds if the driver was spinning in a loop. This results in a lot of spurious stack traces in the kernel log. Fix this by limiting it to printing one stack trace for each PE freeze. If the driver is truely stuck the kernel's hung task detector is better suited to reporting the probelm anyway. Signed-off-by: Oliver O'Halloran Reviewed-by: Sam Bobroff Tested-by: Sam Bobroff Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191016012536.22588-1-oohall@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/kernel/eeh.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index bc8a551013be9..c35069294ecfb 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -503,7 +503,7 @@ int eeh_dev_check_failure(struct eeh_dev *edev) rc = 1; if (pe->state & EEH_PE_ISOLATED) { pe->check_count++; - if (pe->check_count % EEH_MAX_FAILS == 0) { + if (pe->check_count == EEH_MAX_FAILS) { dn = pci_device_to_OF_node(dev); if (dn) location = of_get_property(dn, "ibm,loc-code", -- 2.25.1