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 9F3A6C7EE23 for ; Tue, 9 May 2023 22:19:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234872AbjEIWTE (ORCPT ); Tue, 9 May 2023 18:19:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235609AbjEIWTA (ORCPT ); Tue, 9 May 2023 18:19:00 -0400 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08FE5173B; Tue, 9 May 2023 15:18:41 -0700 (PDT) Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 349MI650127975; Tue, 9 May 2023 17:18:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1683670686; bh=VPo0BABSLp/yxbXX4gZZ7G7cTOoL07it58TctQ+j5ik=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=FGFqDMbHMXIrXIfgOe9p+FKAufbeVHkv6noeC/6wdAOteglVO+Y047zkLUvgqSNKm d32djcWLDbZpnBTwGiSxye3N74r35VrpPZX009V9Jw2fO9L5WsRWjur2d/e1boIE78 fs11K2clqx9U+Xg9f7re/YsX3IvUS7EsFQV6KYjM= Received: from DFLE115.ent.ti.com (dfle115.ent.ti.com [10.64.6.36]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 349MI6FS087928 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 9 May 2023 17:18:06 -0500 Received: from DFLE111.ent.ti.com (10.64.6.32) by DFLE115.ent.ti.com (10.64.6.36) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 9 May 2023 17:18:06 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE111.ent.ti.com (10.64.6.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Tue, 9 May 2023 17:18:06 -0500 Received: from [128.247.81.95] (ileaxei01-snat2.itg.ti.com [10.180.69.6]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 349MI6D8046289; Tue, 9 May 2023 17:18:06 -0500 Message-ID: <84e5b09e-f8b9-15ae-4871-e5e4c4f4a470@ti.com> Date: Tue, 9 May 2023 17:18:06 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v4 2/4] can: m_can: Add hrtimer to generate software interrupt To: Marc Kleine-Budde CC: Chandrasekar Ramakrishnan , Wolfgang Grandegger , Krzysztof Kozlowski , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , , , , Schuyler Patton , Nishanth Menon , Vignesh Raghavendra , Tero Kristo , Rob Herring , , , Oliver Hartkopp , Simon Horman References: <20230501224624.13866-1-jm@ti.com> <20230501224624.13866-3-jm@ti.com> <20230502-twiddling-threaten-d032287d4630-mkl@pengutronix.de> Content-Language: en-US From: Judith Mendez In-Reply-To: <20230502-twiddling-threaten-d032287d4630-mkl@pengutronix.de> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org Hello Marc, On 5/2/23 01:37, Marc Kleine-Budde wrote: > On 01.05.2023 17:46:22, Judith Mendez wrote: >> Add an hrtimer to MCAN class device. Each MCAN will have its own >> hrtimer instantiated if there is no hardware interrupt found and >> poll-interval property is defined in device tree M_CAN node. >> >> The hrtimer will generate a software interrupt every 1 ms. In >> hrtimer callback, we check if there is a transaction pending by >> reading a register, then process by calling the isr if there is. >> >> Signed-off-by: Judith Mendez > > I think this patch is as good as it gets, given the HW and SW > limitations of the coprocessor. > > Some minor nitpicks inline. No need to resend from my point of view, > I'll fixup while applying the patch. > > Marc > >> --- >> Changelog: >> v1: >> 1. Sort list of includes >> 2. Create a define for HR_TIMER_POLL_INTERVAL >> 3. Fix indentations and style issues/warnings >> 4. Change polling variable to type bool >> 5. Change platform_get_irq to optional so not to print error msg >> 6. Move error check for addr directly after assignment >> 7. Print appropriate error msg with dev_err_probe insead of dev_dbg >> >> v2: >> 1. Add poll-interval to MCAN class device to check if poll-interval propery is >> present in MCAN node, this enables timer polling method >> 2. Add 'polling' flag to MCAN class device to check if a device is using timer >> polling method >> 3. Check if both timer polling and hardware interrupt are enabled for a MCAN >> device, default to hardware interrupt mode if both are enabled >> 4. Change ms_to_ktime() to ns_to_ktime() >> 5. Remove newlines, tabs, and restructure if/else section >> >> drivers/net/can/m_can/m_can.c | 29 +++++++++++++++++++++-- >> drivers/net/can/m_can/m_can.h | 4 ++++ >> drivers/net/can/m_can/m_can_platform.c | 32 +++++++++++++++++++++++--- >> 3 files changed, 60 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c >> index a5003435802b..e1ac0c1d85a3 100644 >> --- a/drivers/net/can/m_can/m_can.c >> +++ b/drivers/net/can/m_can/m_can.c >> @@ -11,6 +11,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -308,6 +309,9 @@ enum m_can_reg { >> #define TX_EVENT_MM_MASK GENMASK(31, 24) >> #define TX_EVENT_TXTS_MASK GENMASK(15, 0) >> >> +/* Hrtimer polling interval */ >> +#define HRTIMER_POLL_INTERVAL 1 >> + >> /* The ID and DLC registers are adjacent in M_CAN FIFO memory, >> * and we can save a (potentially slow) bus round trip by combining >> * reads and writes to them. >> @@ -1587,6 +1591,11 @@ static int m_can_close(struct net_device *dev) >> if (!cdev->is_peripheral) >> napi_disable(&cdev->napi); >> >> + if (cdev->polling) { >> + dev_dbg(cdev->dev, "Disabling the hrtimer\n"); >> + hrtimer_cancel(&cdev->hrtimer); >> + } >> + >> m_can_stop(dev); >> m_can_clk_stop(cdev); >> free_irq(dev->irq, dev); >> @@ -1793,6 +1802,18 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, >> return NETDEV_TX_OK; >> } >> >> +static enum hrtimer_restart hrtimer_callback(struct hrtimer *timer) >> +{ >> + struct m_can_classdev *cdev = container_of(timer, struct >> + m_can_classdev, hrtimer); >> + >> + m_can_isr(0, cdev->net); >> + >> + hrtimer_forward_now(timer, ms_to_ktime(HRTIMER_POLL_INTERVAL)); >> + >> + return HRTIMER_RESTART; >> +} >> + >> static int m_can_open(struct net_device *dev) >> { >> struct m_can_classdev *cdev = netdev_priv(dev); >> @@ -1827,13 +1848,17 @@ static int m_can_open(struct net_device *dev) >> } >> >> INIT_WORK(&cdev->tx_work, m_can_tx_work_queue); >> - > > unrelated change > >> err = request_threaded_irq(dev->irq, NULL, m_can_isr, >> IRQF_ONESHOT, >> dev->name, dev); >> - } else { >> + } else if (!cdev->polling) { >> err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name, >> dev); >> + } else { >> + dev_dbg(cdev->dev, "Start hrtimer\n"); >> + cdev->hrtimer.function = &hrtimer_callback; >> + hrtimer_start(&cdev->hrtimer, ms_to_ktime(HRTIMER_POLL_INTERVAL), >> + HRTIMER_MODE_REL_PINNED); >> } >> >> if (err < 0) { >> diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h >> index a839dc71dc9b..e9db5cce4e68 100644 >> --- a/drivers/net/can/m_can/m_can.h >> +++ b/drivers/net/can/m_can/m_can.h >> @@ -15,6 +15,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -93,6 +94,9 @@ struct m_can_classdev { >> int is_peripheral; >> >> struct mram_cfg mcfg[MRAM_CFG_NUM]; >> + >> + struct hrtimer hrtimer; >> + bool polling; >> }; >> >> struct m_can_classdev *m_can_class_allocate_dev(struct device *dev, int sizeof_priv); >> diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c >> index 9c1dcf838006..0fcb436298f8 100644 >> --- a/drivers/net/can/m_can/m_can_platform.c >> +++ b/drivers/net/can/m_can/m_can_platform.c >> @@ -5,6 +5,7 @@ >> // >> // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/ >> >> +#include >> #include >> #include >> >> @@ -96,12 +97,37 @@ static int m_can_plat_probe(struct platform_device *pdev) >> goto probe_fail; >> >> addr = devm_platform_ioremap_resource_byname(pdev, "m_can"); >> - irq = platform_get_irq_byname(pdev, "int0"); >> - if (IS_ERR(addr) || irq < 0) { >> - ret = -EINVAL; >> + if (IS_ERR(addr)) { >> + ret = PTR_ERR(addr); >> goto probe_fail; >> } >> >> + irq = platform_get_irq_byname_optional(pdev, "int0"); >> + if (irq == -EPROBE_DEFER) { >> + ret = -EPROBE_DEFER; >> + goto probe_fail; >> + } >> + >> + if (device_property_present(mcan_class->dev, "poll-interval")) >> + mcan_class->polling = 1; > > true > >> + >> + if (!mcan_class->polling && irq < 0) { >> + ret = -ENXIO; >> + dev_err_probe(mcan_class->dev, ret, "IRQ int0 not found and polling not activated\n"); >> + goto probe_fail; >> + } >> + >> + if (mcan_class->polling) { >> + if (irq > 0) { >> + mcan_class->polling = 0; > > false > >> + dev_dbg(mcan_class->dev, "Polling enabled and hardware IRQ found, use hardware IRQ\n"); > > "...using hardware IRQ" > > Use dev_info(), as there is something not 100% correct with the DT. Is it dev_info or dev_dbg? I used to have dev_info since it was nice to see when polling was enabled. Also, I had seen this print and the next as informative prints, hence the dev_info(). However, I was told in this review process to change to dev_dbg. Which is correct? >> + } else { >> + dev_dbg(mcan_class->dev, "Polling enabled, initialize hrtimer"); >> + hrtimer_init(&mcan_class->hrtimer, CLOCK_MONOTONIC, >> + HRTIMER_MODE_REL_PINNED); >> + } >> + } >> + >> /* message ram could be shared */ >> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram"); >> if (!res) { >> -- >> 2.17.1 >> >> > regards, Judith