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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 18256C433DF for ; Mon, 12 Oct 2020 02:46:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC4C620776 for ; Mon, 12 Oct 2020 02:46:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726104AbgJLCqC (ORCPT ); Sun, 11 Oct 2020 22:46:02 -0400 Received: from mga12.intel.com ([192.55.52.136]:59575 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725978AbgJLCqC (ORCPT ); Sun, 11 Oct 2020 22:46:02 -0400 IronPort-SDR: +RHDE0ClzKoPSPv62NE0pBUIDj3qmDdUEELEOrz0KYDYgtVU5xfU6HXDy2wrSGaLFFuKnn8Q/V SVFs/M0/LBTA== X-IronPort-AV: E=McAfee;i="6000,8403,9771"; a="145002787" X-IronPort-AV: E=Sophos;i="5.77,365,1596524400"; d="scan'208";a="145002787" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Oct 2020 19:46:01 -0700 IronPort-SDR: pqtrKKIQB/Y0bo3tr4jguTlRbWSSgC/KtZDbP+DtUKPs7Rw+OSvc7BVZy0hLmJtfKA8xGHJ+l9 vqkce2C9prdQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,365,1596524400"; d="scan'208";a="529767360" Received: from yilunxu-optiplex-7050.sh.intel.com (HELO localhost) ([10.239.159.141]) by orsmga005.jf.intel.com with ESMTP; 11 Oct 2020 19:45:58 -0700 Date: Mon, 12 Oct 2020 10:41:00 +0800 From: Xu Yilun To: Tom Rix Cc: mdf@kernel.org, krzk@kernel.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, lgoncalv@redhat.com, hao.wu@intel.com, yilun.xu@intel.com Subject: Re: [PATCH v9 1/6] fpga: dfl: fix the definitions of type & feature_id for dfl devices Message-ID: <20201012024100.GC29436@yilunxu-OptiPlex-7050> References: <1602313793-21421-1-git-send-email-yilun.xu@intel.com> <1602313793-21421-2-git-send-email-yilun.xu@intel.com> <8786ca8f-7edd-d7b1-7eca-6447814c6e5e@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8786ca8f-7edd-d7b1-7eca-6447814c6e5e@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On Sat, Oct 10, 2020 at 08:07:07AM -0700, Tom Rix wrote: > > On 10/10/20 12:09 AM, Xu Yilun wrote: > > The value of the field dfl_device.type comes from the 12 bits register > > field DFH_ID according to DFL spec. So this patch changes the definition > > of the type field to u16. > > > > Also it is not necessary to illustrate the valid bits of the type field > > in comments. Instead we should explicitly define the possible values in > > the enumeration type for it, because they are shared by hardware spec. > > We should not let the compiler decide these values. > > > > Similar changes are also applied to dfl_device.feature_id. > > > > This patch also fixed the MODALIAS format according to the changes > > above. > > > > Signed-off-by: Xu Yilun > > --- > > v9: no change > > --- > > drivers/fpga/dfl.c | 3 +-- > > drivers/fpga/dfl.h | 14 +++++++------- > > 2 files changed, 8 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > > index b450870..5a6ba3b 100644 > > --- a/drivers/fpga/dfl.c > > +++ b/drivers/fpga/dfl.c > > @@ -298,8 +298,7 @@ static int dfl_bus_uevent(struct device *dev, struct kobj_uevent_env *env) > > { > > struct dfl_device *ddev = to_dfl_dev(dev); > > > > - /* The type has 4 valid bits and feature_id has 12 valid bits */ > > - return add_uevent_var(env, "MODALIAS=dfl:t%01Xf%03X", > > + return add_uevent_var(env, "MODALIAS=dfl:t%04Xf%04X", > > ddev->type, ddev->feature_id); > > } > > > > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h > > index 5dc758f..ac373b1 100644 > > --- a/drivers/fpga/dfl.h > > +++ b/drivers/fpga/dfl.h > > @@ -520,19 +520,19 @@ long dfl_feature_ioctl_set_irq(struct platform_device *pdev, > > * enum dfl_id_type - define the DFL FIU types > > */ > > enum dfl_id_type { > > - FME_ID, > > - PORT_ID, > > + FME_ID = 0, > > + PORT_ID = 1, > > This is redundant, why make this change ? These values are shared by hardware spec, so it is suggested that the values of the enum type should be explicitly set, otherwise the compiler is in its right to do whatever it wants with them (within reason...) Please see the original discussion: https://lore.kernel.org/linux-fpga/20200923055436.GA2629915@kroah.com/ Thanks, Yilun > > Tom > > > DFL_ID_MAX, > > }; > > > > /** > > * struct dfl_device_id - dfl device identifier > > - * @type: contains 4 bits DFL FIU type of the device. See enum dfl_id_type. > > - * @feature_id: contains 12 bits feature identifier local to its DFL FIU type. > > + * @type: DFL FIU type of the device. See enum dfl_id_type. > > + * @feature_id: feature identifier local to its DFL FIU type. > > * @driver_data: driver specific data. > > */ > > struct dfl_device_id { > > - u8 type; > > + u16 type; > > u16 feature_id; > > unsigned long driver_data; > > }; > > @@ -543,7 +543,7 @@ struct dfl_device_id { > > * @dev: generic device interface. > > * @id: id of the dfl device. > > * @type: type of DFL FIU of the device. See enum dfl_id_type. > > - * @feature_id: 16 bits feature identifier local to its DFL FIU type. > > + * @feature_id: feature identifier local to its DFL FIU type. > > * @mmio_res: mmio resource of this dfl device. > > * @irqs: list of Linux IRQ numbers of this dfl device. > > * @num_irqs: number of IRQs supported by this dfl device. > > @@ -553,7 +553,7 @@ struct dfl_device_id { > > struct dfl_device { > > struct device dev; > > int id; > > - u8 type; > > + u16 type; > > u16 feature_id; > > struct resource mmio_res; > > int *irqs;