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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 97F1FC56202 for ; Tue, 24 Nov 2020 19:53:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CBA5206D4 for ; Tue, 24 Nov 2020 19:53:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="1yYpmRyq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728910AbgKXTxI (ORCPT ); Tue, 24 Nov 2020 14:53:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:34698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727731AbgKXTxH (ORCPT ); Tue, 24 Nov 2020 14:53:07 -0500 Received: from localhost (129.sub-72-107-112.myvzw.com [72.107.112.129]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 28F9C206D4; Tue, 24 Nov 2020 19:53:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606247587; bh=zE+2MmKDRI9sbrGlq7BkuT6Mkm+WrAFVxPD0rd7A6wU=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=1yYpmRyq/UEAZAec4JEVeWrxcK3k4oEXBlVgKHW3hukB0gmcv5/OfqVAgY8jKeM9r Xpk7upd2rteVBwLSny6HTcY4FazU/l89Me9l6GEh5dPQUgQCfnkbrK9xPqwoglU2O7 zj45MJgXq/FUUcQ15AYuEzjnBiAn6uR+wEbNK+P8= Date: Tue, 24 Nov 2020 13:53:05 -0600 From: Bjorn Helgaas To: Puranjay Mohan Cc: bjorn@helgaas.com, linux-pci@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, skhan@linuxfoundation.org Subject: Re: [PATCH] PCI: Change return type of pci_find_capability() Message-ID: <20201124195305.GA584380@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201117191718.17885-1-puranjay12@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Nov 18, 2020 at 12:47:18AM +0530, Puranjay Mohan wrote: > PCI Capabilities are linked in a list that must appear in the first 256 bytes of config space. > The Capabilities Pointer register at 0x34 contains the address of the first Capability in the list. > Each Capability contains an 8 bit "Next Capability Pointer" that is set to 0x00 in the last item of the list. > > Change the return type of pci_find_capability() from int to u8 to match the specification. Nits: Be more specific in subject, e.g., "Return u8 from pci_find_capability()". Wrap commit log to fit in 78 columns. Add blank lines between paragraphs. The 0x34 address is accurate but not relevant to this patch. > Signed-off-by: Puranjay Mohan > --- > drivers/pci/pci.c | 4 ++-- > include/linux/pci.h | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 6d4d5a2f923d..05ac8a493e6b 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -477,9 +477,9 @@ static int __pci_bus_find_cap_start(struct pci_bus *bus, > * %PCI_CAP_ID_PCIX PCI-X > * %PCI_CAP_ID_EXP PCI Express > */ > -int pci_find_capability(struct pci_dev *dev, int cap) > +u8 pci_find_capability(struct pci_dev *dev, int cap) > { > - int pos; > + u8 pos; > > pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); Also change the signatures of __pci_bus_find_cap_start(), __pci_find_next_cap(), __pci_find_next_cap_ttl() to match. > if (pos) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 22207a79762c..19a817702ea9 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1063,7 +1063,7 @@ void pci_sort_breadthfirst(void); > > /* Generic PCI functions exported to card drivers */ > > -int pci_find_capability(struct pci_dev *dev, int cap); > +u8 pci_find_capability(struct pci_dev *dev, int cap); > int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap); > int pci_find_ext_capability(struct pci_dev *dev, int cap); > int pci_find_next_ext_capability(struct pci_dev *dev, int pos, int cap); > @@ -1719,7 +1719,7 @@ static inline int __pci_register_driver(struct pci_driver *drv, > static inline int pci_register_driver(struct pci_driver *drv) > { return 0; } > static inline void pci_unregister_driver(struct pci_driver *drv) { } > -static inline int pci_find_capability(struct pci_dev *dev, int cap) > +static inline u8 pci_find_capability(struct pci_dev *dev, int cap) > { return 0; } > static inline int pci_find_next_capability(struct pci_dev *dev, u8 post, > int cap) > -- > 2.27.0 >