From patchwork Thu Nov 18 14:03:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Naveen Naidu X-Patchwork-Id: 1556667 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=JG5K9Trd; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by bilbo.ozlabs.org (Postfix) with ESMTP id 4Hw1m54nS3z9s5P for ; Fri, 19 Nov 2021 01:05:41 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232287AbhKROIk (ORCPT ); Thu, 18 Nov 2021 09:08:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232281AbhKROIk (ORCPT ); Thu, 18 Nov 2021 09:08:40 -0500 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5545FC061570; Thu, 18 Nov 2021 06:05:40 -0800 (PST) Received: by mail-pl1-x62d.google.com with SMTP id b11so5299042pld.12; Thu, 18 Nov 2021 06:05:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=nZn4SxDZvh+tavMY8+enW7L1nqxNB0bRzV0t3A5PNmg=; b=JG5K9Trd1o3s4rrA6V+Ay1LKEJnXRI5kjwDECp3bKxrUj+eDe+iJmCOxM5RXaT7FBj wEHlIjohorJgsIIb/ELmE0bh34ntCQCc9Wp6Vmbtq00W4kdPbwQ6n4rCIphJNy7Fju6Q 4Zpx3SndARG4CvzkOtorq1A1jbfbAR1UKd3x99AELcG7XRA9l2y5lW2KpA3wWXJEJBHb OKyIlxB8PqJ9RUWcV89WDhgxB/ptMVQjvisEzBZa7VsepHzxGFkyKJdWXHT6u4GqyuO6 STb6sTk5n2jjW1HfkB+mxZZlHikXjN73pqTyz7JjsHdJXKPEEuHDwx3tYkTN2fb8yLz3 Mwow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=nZn4SxDZvh+tavMY8+enW7L1nqxNB0bRzV0t3A5PNmg=; b=wm2MvKLOHifsAbq9BbVVhuIofB3zlwTBKkqd9QCtwQ7Nrkrr3IHxM+MC65WK9PFOZp fU+4Ku0xe9O+XUC9QNUeZwMZ8gDGQT6jAwCNYD+M2iOdaNJnQvJfh0gFc5lWLAhFvCdQ e0oKQ0GzyK4We52A2H4x/xt+KXMfHvS5wwXsX9qkyH68ZhBDaOgFz/4bBsKlTL02HAaK ah6ybTZx9zZdHmHibteMsMeLJDMbcpYSeJLpYkdQ/Q0UzRcP+t8ady1u1oMTpl0qvT22 Tf25ogl3a+pbiRp7+YQceA/ghf8uZdY4CS1GzTgx8PBNjgYWzUZN2LgyQTOboboqbsjs 5uXw== X-Gm-Message-State: AOAM5312HL0RpLZ/T54ZcIUy1A1/NgyNGqIqUKvPvLQAEvkoPwkIQYmQ 8gWeoiUNAaZu7huc74N+oQI= X-Google-Smtp-Source: ABdhPJz9L+8is2Ip8jLLWfzTNi/us5Q4tilWZCGXKU5MU+FnoFZb+E4/5NFsc5dQ6k9M0TzIAtqBrA== X-Received: by 2002:a17:90a:d49:: with SMTP id 9mr11086261pju.115.1637244339812; Thu, 18 Nov 2021 06:05:39 -0800 (PST) Received: from localhost.localdomain ([2406:7400:63:2c47:5ffe:fc34:61f0:f1ea]) by smtp.gmail.com with ESMTPSA id x14sm2822878pjl.27.2021.11.18.06.05.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Nov 2021 06:05:39 -0800 (PST) From: Naveen Naidu To: bhelgaas@google.com Cc: Naveen Naidu , linux-kernel-mentees@lists.linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, Lorenzo Pieralisi , Rob Herring , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com (maintainer:BROADCOM IPROC ARM ARCHITECTURE), linux-arm-kernel@lists.infradead.org (moderated list:BROADCOM IPROC ARM ARCHITECTURE) Subject: [PATCH v4 06/25] PCI: iproc: Remove redundant error fabrication when device read fails Date: Thu, 18 Nov 2021 19:33:16 +0530 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org An MMIO read from a PCI device that doesn't exist or doesn't respond causes a PCI error. There's no real data to return to satisfy the CPU read, so most hardware fabricates ~0 data. The host controller drivers sets the error response values (~0) and returns an error when faulty hardware read occurs. But the error response value (~0) is already being set in PCI_OP_READ and PCI_USER_READ_CONFIG whenever a read by host controller driver fails. Thus, it's no longer necessary for the host controller drivers to fabricate any error response. This helps unify PCI error response checking and make error check consistent and easier to find. Signed-off-by: Naveen Naidu --- drivers/pci/controller/pcie-iproc.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c index 36b9d2c46cfa..b3e75bc61ff1 100644 --- a/drivers/pci/controller/pcie-iproc.c +++ b/drivers/pci/controller/pcie-iproc.c @@ -659,10 +659,8 @@ static int iproc_pci_raw_config_read32(struct iproc_pcie *pcie, void __iomem *addr; addr = iproc_pcie_map_cfg_bus(pcie, 0, devfn, where & ~0x3); - if (!addr) { - *val = ~0; + if (!addr) return PCIBIOS_DEVICE_NOT_FOUND; - } *val = readl(addr);