From patchwork Tue Jan 5 02:14:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Song Bao Hua \(Barry Song\)" X-Patchwork-Id: 357148 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 CB1C3C433DB for ; Tue, 5 Jan 2021 02:20:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CACD2251F for ; Tue, 5 Jan 2021 02:20:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727757AbhAECUJ (ORCPT ); Mon, 4 Jan 2021 21:20:09 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:10382 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727701AbhAECUJ (ORCPT ); Mon, 4 Jan 2021 21:20:09 -0500 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4D8x4S27l9z7Q5h; Tue, 5 Jan 2021 10:18:32 +0800 (CST) Received: from SWX921481.china.huawei.com (10.126.203.185) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.498.0; Tue, 5 Jan 2021 10:19:14 +0800 From: Barry Song To: , , , , CC: , Barry Song , "Dmitry Torokhov" Subject: [PATCH v2] genirq: add IRQF_NO_AUTOEN for request_irq Date: Tue, 5 Jan 2021 15:14:11 +1300 Message-ID: <20210105021411.34020-1-song.bao.hua@hisilicon.com> X-Mailer: git-send-email 2.21.0.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.126.203.185] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Many drivers don't want interrupts enabled automatically due to request_irq(). So they are handling this issue by either way of the below two: (1) irq_set_status_flags(irq, IRQ_NOAUTOEN); request_irq(dev, irq...); (2) request_irq(dev, irq...); disable_irq(irq); The code in the second way is silly and unsafe. In the small time gap between request_irq() and disable_irq(), interrupts can still come. The code in the first way is safe though we might be able to do it in the generic irq code. With this patch, drivers can request_irq with IRQF_NO_AUTOEN flag. They will need neither irq_set_status_flags() nor disable_irq(). Hundreds of drivers with this problem will be handled afterwards. Cc: Dmitry Torokhov Signed-off-by: Barry Song --- -v2: refuse the cases IRQF_NO_AUTOEN + IRQF_DISABLED are both set with respect to Dmitry's feedback in v1 include/linux/interrupt.h | 3 +++ kernel/irq/manage.c | 8 ++++++++ kernel/irq/settings.h | 10 ++++++++++ 3 files changed, 21 insertions(+) diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index bb8ff9083e7d..0f22d277078c 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -61,6 +61,8 @@ * interrupt handler after suspending interrupts. For system * wakeup devices users need to implement wakeup detection in * their interrupt handlers. + * IRQF_NO_AUTOEN - Don't enable IRQ automatically when users request it. Users + * will enable it explicitly by enable_irq() later. */ #define IRQF_SHARED 0x00000080 #define IRQF_PROBE_SHARED 0x00000100 @@ -74,6 +76,7 @@ #define IRQF_NO_THREAD 0x00010000 #define IRQF_EARLY_RESUME 0x00020000 #define IRQF_COND_SUSPEND 0x00040000 +#define IRQF_NO_AUTOEN 0x00080000 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ab8567f32501..2b28314e2572 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1693,6 +1693,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) irqd_set(&desc->irq_data, IRQD_NO_BALANCING); } + if (new->flags & IRQF_NO_AUTOEN) + irq_settings_set_noautoen(desc); + if (irq_settings_can_autoenable(desc)) { irq_startup(desc, IRQ_RESEND, IRQ_START_COND); } else { @@ -2086,10 +2089,15 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler, * which interrupt is which (messes up the interrupt freeing * logic etc). * + * Also shared interrupts do not go well with disabling auto enable. + * The sharing interrupt might request it while it's still disabled + * and then wait for interrupts forever. + * * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and * it cannot be set along with IRQF_NO_SUSPEND. */ if (((irqflags & IRQF_SHARED) && !dev_id) || + ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) || (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) || ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND))) return -EINVAL; diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h index 403378b9947b..a28958a9c548 100644 --- a/kernel/irq/settings.h +++ b/kernel/irq/settings.h @@ -145,6 +145,16 @@ static inline bool irq_settings_can_move_pcntxt(struct irq_desc *desc) return desc->status_use_accessors & _IRQ_MOVE_PCNTXT; } +static inline void irq_settings_clr_noautoen(struct irq_desc *desc) +{ + desc->status_use_accessors &= ~_IRQ_NOAUTOEN; +} + +static inline void irq_settings_set_noautoen(struct irq_desc *desc) +{ + desc->status_use_accessors |= _IRQ_NOAUTOEN; +} + static inline bool irq_settings_can_autoenable(struct irq_desc *desc) { return !(desc->status_use_accessors & _IRQ_NOAUTOEN);