From patchwork Fri May 31 01:04:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 13681019 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C3F1A1CFA8; Fri, 31 May 2024 01:04:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717117461; cv=none; b=ZxYeR/DeXSORfLQVppTAU5rAPqteBJx6uO2zVm3S0Sw0PjGrXf4e+IYdWXhKZCgwMhycBHdhbvkjuovgEGdQWYCSTsyD48YJUpYiKtghAe6uuNyOOA85jOVutqceMIl+p0GwFNr+pGRORiSxje5LteLS3VWT5BwxJYdUSLWsHAM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717117461; c=relaxed/simple; bh=abAk7mA+rsV5IZXkrCgVcQjrR1gtG6P8LrgYPddhcik=; h=Subject:From:To:Cc:Date:Message-ID:MIME-Version:Content-Type; b=MI8vM+KBMaZBcF08Yaj8aZ+RKu8GVieQaA6wgLJwqDFc5YQVvnmzv3iavCyXf/dBUC7cPWJdoJhMyupVwzhgCVy7IMuRwsKxa91grIWY6EXVxGKn0bgUQrqUmgOseo3F3HX+sViyTU6HQWnO/SH3gfTqXSh4BaZW4eYo1NzU8Nc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=JNe/DFRC; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="JNe/DFRC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1717117459; x=1748653459; h=subject:from:to:cc:date:message-id:mime-version: content-transfer-encoding; bh=abAk7mA+rsV5IZXkrCgVcQjrR1gtG6P8LrgYPddhcik=; b=JNe/DFRCBsYkdgZjAkmMBfgj7EcgI1CJeVzR2O8fCwChDsimkUd0CDPl mKZ2igGKcQjf7q3cB/mMyFVaG+lxKWQyZVYAn5DUTVfpjdpOiks8Zs4kH +HSaZIrdjLnYcPCmPxdDn9dSYOf90R+K6LGsdT+BECtOmocSXYsUSqkAA gUPwePqol026Pd+NY2t8jtZ9G7Wd0xP3cJst1dSHnty3mTv3AYXt964cz g5EJuPS8tsSok1RiyRY3Hqm3V6mDoE2MRGqHqs6A7+g+YADh0NWhrlo8F NrlEDSumnWzoHZJyYGJIXPopM4B6cEMjSHBlupp7b1aAkA51iV/lpDIrB A==; X-CSE-ConnectionGUID: 06UbkPW1TiCw9hzZX5Dogg== X-CSE-MsgGUID: unOAgcCJThmkqGKRrlrXyw== X-IronPort-AV: E=McAfee;i="6600,9927,11088"; a="24308742" X-IronPort-AV: E=Sophos;i="6.08,202,1712646000"; d="scan'208";a="24308742" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 May 2024 18:04:19 -0700 X-CSE-ConnectionGUID: G487IlTsRqatTR+8oN4qKQ== X-CSE-MsgGUID: dwdlnVFbTHehSUibmMlevA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,202,1712646000"; d="scan'208";a="36624024" Received: from spittala-mobl3.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.209.84.244]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 May 2024 18:04:19 -0700 Subject: [PATCH v2 0/3] PCI: Revert / replace the cfg_access_lock lockdep mechanism From: Dan Williams To: bhelgaas@google.com Cc: Dave Jiang , Imre Deak , Jani Saarinen , linux-pci@vger.kernel.org, linux-cxl@vger.kernel.org Date: Thu, 30 May 2024 18:04:18 -0700 Message-ID: <171711745834.1628941.5259278474013108507.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Changes since v1 [1]: - split out the new warning into its own patch (Bjorn) - include the provisional fix to the pci_reset_bus() path [1]: http://lore.kernel.org/r/171709637423.1568751.11773767969980847536.stgit@dwillia2-xfh.jf.intel.com Hi Bjorn, Here is the targeted revert of the cfg_access_lock lockdep infrastructure, but with the new proposed warning for catching "unlocked pci_bridge_secondary_bus_reset()" events broken out into its own change. I also included the proposed fix for at least one known case where pci_bridge_secondary_bus_reset() is being called without cfg_access_lock. Given there may be more cases to unwind, and the fact that I am not convinced patch3 will be problem free I would, as you suggested, consider patch2 and patch3 v6.11 material. Patch1 is urgent for v6.10-rc to put out these lockdep false positive reports. Tested-by: Hans de Goede --- Dan Williams (3): PCI: Revert the cfg_access_lock lockdep mechanism PCI: Warn on missing cfg_access_lock during secondary bus reset PCI: Add missing bridge lock to pci_bus_lock() drivers/pci/access.c | 4 ---- drivers/pci/pci.c | 8 +++++++- drivers/pci/probe.c | 3 --- include/linux/lockdep.h | 5 ----- include/linux/pci.h | 2 -- 5 files changed, 7 insertions(+), 15 deletions(-) base-commit: 56fb6f92854f29dcb6c3dc3ba92eeda1b615e88c