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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 20D59C6377B for ; Wed, 21 Jul 2021 20:25:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0683B60698 for ; Wed, 21 Jul 2021 20:25:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231490AbhGUTo6 (ORCPT ); Wed, 21 Jul 2021 15:44:58 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:49368 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229729AbhGUTo6 (ORCPT ); Wed, 21 Jul 2021 15:44:58 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1626899133; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/CthbpuGZ/4QYOJnFtoyw2VJqPR9q9LtmXqXub96q+k=; b=cTYlhxb8dGvUls4dX0qq5oaVHOxNm7MYH/CHV24oIScKMCKsUVF/oAkignqKt1L05Z4Ms1 yuhqj4/PZXBby3VMqDC7d49tr+RVPldtMn9btuedvliqedchBFaznNpVuMn+mxweFh5UAv epfElup/3o8WlZGUHw2USdI/4QbJ5aCqz08HTfEYhsD+WKa8RYE/Oezgp2Z4DU0ey0ifmF hDd9muJbxCy5ydu8LPdwsYPaUw5ITmIy7WgHtC2s+kB588DpHYNGcMuzO1i+qnfQHcOrm0 23SJVGP/l6qW7IYX7oPAZu/qPpk3WWQDk9JvF1XmNNQfKNjgSrcA6HUTdFzX/Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1626899133; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/CthbpuGZ/4QYOJnFtoyw2VJqPR9q9LtmXqXub96q+k=; b=kohnLQCXgZGWJwAmpzUFf/Gws9c3kRvfJVCKy3S7dZ6xnEpGVByaElYwpltlrQeSB8QP/B DHq6jQkceVx3fnDw== To: Rasmus Villemoes , Linus Walleij , Bartosz Golaszewski Cc: Song Hui , Rasmus Villemoes , stable@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Revert "gpio: mpc8xxx: change the gpio interrupt flags." In-Reply-To: <20210702133712.128611-1-linux@rasmusvillemoes.dk> References: <20210702133712.128611-1-linux@rasmusvillemoes.dk> Date: Wed, 21 Jul 2021 22:25:33 +0200 Message-ID: <87v953pg76.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Jul 02 2021 at 15:37, Rasmus Villemoes wrote: > This reverts commit 3d5bfbd9716318b1ca5c38488aa69f64d38a9aa5. > > When booting with threadirqs, it causes a splat > > WARNING: CPU: 0 PID: 29 at kernel/irq/handle.c:159 __handle_irq_event_percpu+0x1ec/0x27c > irq 66 handler irq_default_primary_handler+0x0/0x1c enabled interrupts > > That splat later went away with commit 81e2073c175b ("genirq: Disable > interrupts for force threaded handlers"), which got backported to > -stable. However, when running an -rt kernel, the splat still > exists. Moreover, quoting Thomas Gleixner [1] > > But 3d5bfbd97163 ("gpio: mpc8xxx: change the gpio interrupt flags.") > has nothing to do with that: > > "Delete the interrupt IRQF_NO_THREAD flags in order to gpio interrupts > can be threaded to allow high-priority processes to preempt." > > This changelog is blatantly wrong. In mainline forced irq threads > have always been invoked with softirqs disabled, which obviously > makes them non-preemptible. > > So the patch didn't even do what its commit log said. > > [1] https://lore.kernel.org/lkml/871r8zey88.ffs@nanos.tec.linutronix.de/ > > Cc: stable@vger.kernel.org # v5.9+ > Signed-off-by: Rasmus Villemoes > --- > Thomas, please correct me if I misinterpreted your explanation. Nothing to correct here. Reviewed-by: Thomas Gleixner