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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B925EC433ED for ; Wed, 7 Apr 2021 12:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8586F60FF0 for ; Wed, 7 Apr 2021 12:53:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352488AbhDGMxc (ORCPT ); Wed, 7 Apr 2021 08:53:32 -0400 Received: from mail-oo1-f49.google.com ([209.85.161.49]:45965 "EHLO mail-oo1-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230234AbhDGMxb (ORCPT ); Wed, 7 Apr 2021 08:53:31 -0400 Received: by mail-oo1-f49.google.com with SMTP id s1-20020a4ac1010000b02901cfd9170ce2so4504562oop.12 for ; Wed, 07 Apr 2021 05:53:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mKDgU1yLjGyHNHcGNUpZAwk4xvj+aA7x3EWVsTIYXaM=; b=ktky2oa7SjHOUUGHPZL3v0zK+ph6KbRsXMb/vOSeKFlYJQkpIaqJAoOIWJCYurYiIK 7Ln9hotcOjAAwXz8Xa1f+Nelao31sEfyVNfIQHWh19myuktnOJ7h/dqc9r7AnpjThaDi l83VYHgWrHyscaXit+2Xy6UMIdN5EwCg3dliS4Hb35PvX560VodnvuAvyNZznAQx6YDn I7CEIM8kXKh3ZarRfgrMwOGIYyiQCO83pOADZdOB60wbBkf7pOCuRTiSRDMhUtao0S1d 2Cs/c39f6jvnJ9NxyCYKHy4LMeZ3tk4Z+WjtRk4JwJfZEYv+jPaegsJW9F9GgUmi7htZ F6pA== X-Gm-Message-State: AOAM530TMOZZE57SWJ2daVzYZsM3hLaptFf9wNLDFPDg0/Q3dRxRYp2p A60MA5xyoO4A0pwqEH1HFjfb4fWEGBlDEsG/85Q= X-Google-Smtp-Source: ABdhPJz8mb1hCS4cIl6U4FHNeJ5uOpyx6a996s7hvJbkQgdnUhn3XTyKvGZy11XSsWh1QMAUgHtEQOPmev/ojEVETtk= X-Received: by 2002:a4a:41cb:: with SMTP id x194mr2961645ooa.1.1617800000246; Wed, 07 Apr 2021 05:53:20 -0700 (PDT) MIME-Version: 1.0 References: <20210329195238.9455-1-acz@semihalf.com> <1c086b9e-d5c2-6e8d-1d81-748935b0dd64@intel.com> <20210330154957.GU2542@lahna.fi.intel.com> In-Reply-To: From: "Rafael J. Wysocki" Date: Wed, 7 Apr 2021 14:53:09 +0200 Message-ID: Subject: Re: [PATCH] resource: Prevent irqresource_disabled() from erasing flags To: Angela Czubak Cc: Mika Westerberg , "Rafael J. Wysocki" , Andrew Morton , John Garry , Linux Kernel Mailing List , upstream@semihalf.com, Dmitry Torokhov , linux-acpi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 7, 2021 at 1:01 PM Angela Czubak wrote: > > On Tue, Mar 30, 2021 at 5:50 PM Mika Westerberg > wrote: > > > > Hi, > > > > On Tue, Mar 30, 2021 at 05:09:42PM +0200, Rafael J. Wysocki wrote: > > > On 3/29/2021 9:52 PM, Angela Czubak wrote: > > > > Do not overwrite flags as it leads to erasing triggering and polarity > > > > information which might be useful in case of hard-coded interrupts. > > > > This way the information can be read later on even though mapping to > > > > APIC domain failed. > > > > > > > > Signed-off-by: Angela Czubak > > > > --- > > > > Some Chromebooks use hard-coded interrupts in their ACPI tables. > > > > This is an excerpt as dumped on Relm: > > > > > > > > ... > > > > Name (_HID, "ELAN0001") // _HID: Hardware ID > > > > Name (_DDN, "Elan Touchscreen ") // _DDN: DOS Device Name > > > > Name (_UID, 0x05) // _UID: Unique ID > > > > Name (ISTP, Zero) > > > > Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings > > > > { > > > > Name (BUF0, ResourceTemplate () > > > > { > > > > I2cSerialBusV2 (0x0010, ControllerInitiated, 0x00061A80, > > > > AddressingMode7Bit, "\\_SB.I2C1", > > > > 0x00, ResourceConsumer, , Exclusive, > > > > ) > > > > Interrupt (ResourceConsumer, Edge, ActiveLow, Exclusive, ,, ) > > > > { > > > > 0x000000B8, > > > > } > > > > }) > > > > Return (BUF0) /* \_SB_.I2C1.ETSA._CRS.BUF0 */ > > > > } > > > > ... > > > > > > > > This interrupt is hard-coded to 0xB8 = 184 which is too high to be mapped > > > > to IO-APIC, so no triggering information is propagated as acpi_register_gsi() > > > > fails and irqresource_disabled() is issued, which leads to erasing triggering > > > > and polarity information. > > > > If that function added its flags instead of overwriting them the correct IRQ > > > > type would be set even for the hard-coded interrupts, which allows device driver > > > > to retrieve it. > > > > Please, let me know if this kind of modification is acceptable. > > > > > > From the quick look it should not be problematic, but it needs to be checked > > > more carefully. > > > > > > Mika, what do you think? > > > > I think it makes sense. We still set IORESOURCE_DISABLED unconditionally > > so this should not cause issues. In theory at least :) > > > Is there anything else you would need me to do regarding the patch? Yes, please resend it with a CC to linux-acpi@vger.kernel.org for more visibility. > I suppose there are more platforms that could benefit from not erasing > the flags, so if this patch is fit for upstream, can we continue the > process? > > > > > include/linux/ioport.h | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > > > > index 55de385c839cf..647744d8514e0 100644 > > > > --- a/include/linux/ioport.h > > > > +++ b/include/linux/ioport.h > > > > @@ -331,7 +331,7 @@ static inline void irqresource_disabled(struct resource *res, u32 irq) > > > > { > > > > res->start = irq; > > > > res->end = irq; > > > > - res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | IORESOURCE_UNSET; > > > > + res->flags |= IORESOURCE_IRQ | IORESOURCE_DISABLED | IORESOURCE_UNSET; > > > > } > > > > extern struct address_space *iomem_get_mapping(void); > > >