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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07000C7618D for ; Thu, 6 Apr 2023 11:05:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236866AbjDFLFg convert rfc822-to-8bit (ORCPT ); Thu, 6 Apr 2023 07:05:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235352AbjDFLFd (ORCPT ); Thu, 6 Apr 2023 07:05:33 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BF8F86B0 for ; Thu, 6 Apr 2023 04:05:18 -0700 (PDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-70-FCYuxC1NPdeaowzkllIknw-1; Thu, 06 Apr 2023 12:05:15 +0100 X-MC-Unique: FCYuxC1NPdeaowzkllIknw-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Thu, 6 Apr 2023 12:05:14 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Thu, 6 Apr 2023 12:05:14 +0100 From: David Laight To: "linux-kernel@vger.kernel.org" , "Thomas Gleixner" , Jason Gunthorpe , "Bjorn Helgaas" CC: Linus Torvalds , Christoph Hellwig Subject: revert bab65e48cb064 PCI/MSI Sanitize MSI-X checks Thread-Topic: revert bab65e48cb064 PCI/MSI Sanitize MSI-X checks Thread-Index: AdlodgFkFYa3Wd45RlGJwWEgKJXFDw== Date: Thu, 6 Apr 2023 11:05:14 +0000 Message-ID: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The change in bab65e48cb064 breaks pci_enable_msix_range(). The intent is to optimise the sanity checks, but it is somewhat overenthusiastic. The interface allows you to ask for a lot of vectors and returns the number that were allocated. However, after the change, you can't request a vector that is higher than the largest the hardware supports. Which makes that rather pointless. So code like: for (i = 0; i < 16; i++) msix_tbl[i].entry = i; nvec = pci_enable_msix_range(dev, msix_tbl, 1, 16); Now returns -22 if the hardware only supports 8 interrupts. Previously it returned 8. I can fix my driver, but I suspect that any code that relies on a smaller number of vectors being returned is now broken. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)