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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 126FFC433B4 for ; Sat, 10 Apr 2021 12:28:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0B8B601FD for ; Sat, 10 Apr 2021 12:28:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234427AbhDJM3D (ORCPT ); Sat, 10 Apr 2021 08:29:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:60130 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234392AbhDJM3D (ORCPT ); Sat, 10 Apr 2021 08:29:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9AD89611AE for ; Sat, 10 Apr 2021 12:28:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618057728; bh=jJM9L8VGUMULEWespnVrhB2m5QplbVSrK7u3PS8oAvM=; h=Date:From:To:Subject:From; b=sgmNvXnymx1GQUJC8OCtagvl5g0WXNB8K7Prby7ZJzV/MZ3ps0FnkrVmiYWni4XI8 n8jpFVPWg35hFmESOnCzYu6/nONhjN6vERiSfv2CqoVyC6Bfgln+suM19OtlYFQA/G nhr3E+oxTNHy95kfijO/3T5SYwRsFAT8jlzLFAGymSKQbS9XDe/aRxYUC6M0HYOvH0 dAUgGGTMcneOJxp05EGt2qPc/ny5/NV7TfgPUl5Y1TiQ93nG3yVRJxGY+arC7i5JIB +KHbucoLGUVQlg10ObyFNkWQv0DVafE3iayrL8pdYz6k+TFkVkDHKoQzcavmFuCKlS QdKd1OuhPQFUA== Received: by pali.im (Postfix) id 35626BEF; Sat, 10 Apr 2021 14:28:45 +0200 (CEST) Date: Sat, 10 Apr 2021 14:28:45 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: linux-pci@vger.kernel.org Subject: PCI service interrupt handlers & access to PCI config space Message-ID: <20210410122845.nhenihbygmcjlegn@pali> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hello! I see that more PCI service drivers in their interrupt handlers are accessing PCI config space. E.g. in PCIe Hot Plug interrupt handler pciehp_isr handler is called pcie_capability_read_word() function. It is correct? Because these capability functions are protected by pci_lock_config() / pci_unlock_config() calls. And what would happen when during execution of reading or writing to PCIe config space (e.g. via pcie_capability_read_word()) is triggered PCIe HP interrupt? Would not enter interrupt handler function in deadlock (waiting for unlocking config space)?