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 74C0AC433FE for ; Mon, 24 Jan 2022 21:04:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1445468AbiAXVDi (ORCPT ); Mon, 24 Jan 2022 16:03:38 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:52258 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1443389AbiAXU4w (ORCPT ); Mon, 24 Jan 2022 15:56:52 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id F294DB81243; Mon, 24 Jan 2022 20:56:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 424FBC340E5; Mon, 24 Jan 2022 20:56:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643057809; bh=bd/N2cLIIyZKGPaNuTPqhxCMHdyWjib1d+RJWqvsz/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gl5/52HE9rkRHItua/QNCN/tn7X8DJtkSiZViZe65HTE/SwwdEoOFJ+yAxdKXLwI+ ji5M2YW71nJugx0EahGrdtSvu6ojJr38FUxFtv5hJSRDEeolpHf3YpoxpJjurCqa+n xXJZHGJJG+wuqj8qY2snQUSTIhRa+RHPLGkt6ZzA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hans Verkuil , Mauro Carvalho Chehab Subject: [PATCH 5.16 0054/1039] media: cec-pin: fix interrupt en/disable handling Date: Mon, 24 Jan 2022 19:30:43 +0100 Message-Id: <20220124184126.962153354@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184125.121143506@linuxfoundation.org> References: <20220124184125.121143506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hans Verkuil commit 713bdfa10b5957053811470d298def9537d9ff13 upstream. The en/disable_irq() functions keep track of the 'depth': i.e. if interrupts are disabled twice, then it needs to enable_irq() calls to enable them again. The cec-pin framework didn't take this into accound and could disable irqs multiple times, and it expected that a single enable_irq() would enable them again. Move all calls to en/disable_irq() to the kthread where it is easy to keep track of the current irq state and ensure that multiple en/disable_irq calls never happen. If interrupts where disabled twice, then they would never turn on again, leaving the CEC adapter in a dead state. Signed-off-by: Hans Verkuil Fixes: 865463fc03ed (media: cec-pin: add error injection support) Cc: Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/cec/core/cec-pin.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) --- a/drivers/media/cec/core/cec-pin.c +++ b/drivers/media/cec/core/cec-pin.c @@ -1033,6 +1033,7 @@ static int cec_pin_thread_func(void *_ad { struct cec_adapter *adap = _adap; struct cec_pin *pin = adap->pin; + bool irq_enabled = false; for (;;) { wait_event_interruptible(pin->kthread_waitq, @@ -1060,6 +1061,7 @@ static int cec_pin_thread_func(void *_ad ns_to_ktime(pin->work_rx_msg.rx_ts)); msg->len = 0; } + if (pin->work_tx_status) { unsigned int tx_status = pin->work_tx_status; @@ -1083,27 +1085,39 @@ static int cec_pin_thread_func(void *_ad switch (atomic_xchg(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED)) { case CEC_PIN_IRQ_DISABLE: - pin->ops->disable_irq(adap); + if (irq_enabled) { + pin->ops->disable_irq(adap); + irq_enabled = false; + } cec_pin_high(pin); cec_pin_to_idle(pin); hrtimer_start(&pin->timer, ns_to_ktime(0), HRTIMER_MODE_REL); break; case CEC_PIN_IRQ_ENABLE: + if (irq_enabled) + break; pin->enable_irq_failed = !pin->ops->enable_irq(adap); if (pin->enable_irq_failed) { cec_pin_to_idle(pin); hrtimer_start(&pin->timer, ns_to_ktime(0), HRTIMER_MODE_REL); + } else { + irq_enabled = true; } break; default: break; } - if (kthread_should_stop()) break; } + if (pin->ops->disable_irq && irq_enabled) + pin->ops->disable_irq(adap); + hrtimer_cancel(&pin->timer); + cec_pin_read(pin); + cec_pin_to_idle(pin); + pin->state = CEC_ST_OFF; return 0; } @@ -1130,13 +1144,7 @@ static int cec_pin_adap_enable(struct ce hrtimer_start(&pin->timer, ns_to_ktime(0), HRTIMER_MODE_REL); } else { - if (pin->ops->disable_irq) - pin->ops->disable_irq(adap); - hrtimer_cancel(&pin->timer); kthread_stop(pin->kthread); - cec_pin_read(pin); - cec_pin_to_idle(pin); - pin->state = CEC_ST_OFF; } return 0; } @@ -1157,11 +1165,8 @@ void cec_pin_start_timer(struct cec_pin if (pin->state != CEC_ST_RX_IRQ) return; - atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED); - pin->ops->disable_irq(pin->adap); - cec_pin_high(pin); - cec_pin_to_idle(pin); - hrtimer_start(&pin->timer, ns_to_ktime(0), HRTIMER_MODE_REL); + atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_DISABLE); + wake_up_interruptible(&pin->kthread_waitq); } static int cec_pin_adap_transmit(struct cec_adapter *adap, u8 attempts,