From patchwork Thu Aug 20 09:23:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 265687 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 B2DC8C433E1 for ; Thu, 20 Aug 2020 10:26:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8298B2075E for ; Thu, 20 Aug 2020 10:26:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597919163; bh=nMJTkO6cj4TOvD4sJ8BX0pSnppY8qiNUN3ChP8pnEHI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mWrKiLf7ra74NlmbygiqhohpiDlWOmC6unzwadCMTrm7mpLTbnpB1hUlquCHGEjdW NRgEf5GMk4mZ4q9Rmuj4exh86CvzRIqYjPvjpDMMy/jhTnV2eiugecNiJ7S4oVhb2y 0wANSEYAFJEvrH/L3QfjYaaTLXI3sZhXawKGj918= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731466AbgHTKZ5 (ORCPT ); Thu, 20 Aug 2020 06:25:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:52270 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731703AbgHTKXO (ORCPT ); Thu, 20 Aug 2020 06:23:14 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 E72FF20658; Thu, 20 Aug 2020 10:23:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597918993; bh=nMJTkO6cj4TOvD4sJ8BX0pSnppY8qiNUN3ChP8pnEHI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EsUaY7NJF5K03NTD8oNatrHDByu8MWygQnxJnq1RA+lAdiu93ptuNGfqAZnUur8pX ve+yYe0JeBvbVZFrkuBmpWjpiTXZamjilC2CTPi80YgPdwhPeXE/brFr9wP+Rs4+do aoEd1eUQs0JlhyZVylKv38pRyhVsq/r6jSX+sR5A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Shevchenko , Lee Jones , Sasha Levin Subject: [PATCH 4.4 145/149] mfd: dln2: Run event handler loop under spinlock Date: Thu, 20 Aug 2020 11:23:42 +0200 Message-Id: <20200820092132.719012294@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820092125.688850368@linuxfoundation.org> References: <20200820092125.688850368@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andy Shevchenko [ Upstream commit 3d858942250820b9adc35f963a257481d6d4c81d ] The event handler loop must be run with interrupts disabled. Otherwise we will have a warning: [ 1970.785649] irq 31 handler lineevent_irq_handler+0x0/0x20 enabled interrupts [ 1970.792739] WARNING: CPU: 0 PID: 0 at kernel/irq/handle.c:159 __handle_irq_event_percpu+0x162/0x170 [ 1970.860732] RIP: 0010:__handle_irq_event_percpu+0x162/0x170 ... [ 1970.946994] Call Trace: [ 1970.949446] [ 1970.951471] handle_irq_event_percpu+0x2c/0x80 [ 1970.955921] handle_irq_event+0x23/0x43 [ 1970.959766] handle_simple_irq+0x57/0x70 [ 1970.963695] generic_handle_irq+0x42/0x50 [ 1970.967717] dln2_rx+0xc1/0x210 [dln2] [ 1970.971479] ? usb_hcd_unmap_urb_for_dma+0xa6/0x1c0 [ 1970.976362] __usb_hcd_giveback_urb+0x77/0xe0 [ 1970.980727] usb_giveback_urb_bh+0x8e/0xe0 [ 1970.984837] tasklet_action_common.isra.0+0x4a/0xe0 ... Recently xHCI driver switched to tasklets in the commit 36dc01657b49 ("usb: host: xhci: Support running urb giveback in tasklet context"). The handle_irq_event_* functions are expected to be called with interrupts disabled and they rightfully complain here because we run in tasklet context with interrupts enabled. Use a event spinlock to protect event handler from being interrupted. Note, that there are only two users of this GPIO and ADC drivers and both of them are using generic_handle_irq() which makes above happen. Fixes: 338a12814297 ("mfd: Add support for Diolan DLN-2 devices") Signed-off-by: Andy Shevchenko Signed-off-by: Lee Jones Signed-off-by: Sasha Levin --- drivers/mfd/dln2.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c index 672831d5ee32e..97a69cd6f1278 100644 --- a/drivers/mfd/dln2.c +++ b/drivers/mfd/dln2.c @@ -294,7 +294,11 @@ static void dln2_rx(struct urb *urb) len = urb->actual_length - sizeof(struct dln2_header); if (handle == DLN2_HANDLE_EVENT) { + unsigned long flags; + + spin_lock_irqsave(&dln2->event_cb_lock, flags); dln2_run_event_callbacks(dln2, id, echo, data, len); + spin_unlock_irqrestore(&dln2->event_cb_lock, flags); } else { /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */ if (dln2_transfer_complete(dln2, urb, handle, echo))