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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 416C7ECE560 for ; Mon, 17 Sep 2018 14:55:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 047DD2147A for ; Mon, 17 Sep 2018 14:55:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 047DD2147A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729030AbeIQUXU (ORCPT ); Mon, 17 Sep 2018 16:23:20 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:51222 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728311AbeIQUXU (ORCPT ); Mon, 17 Sep 2018 16:23:20 -0400 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 2317FDD3145CC; Mon, 17 Sep 2018 22:55:35 +0800 (CST) Received: from [127.0.0.1] (10.202.226.41) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.399.0; Mon, 17 Sep 2018 22:55:25 +0800 Subject: Re: [PATCH v2] serial: 8250_of: Fix for lack of interrupt support To: References: <1535620130-199328-1-git-send-email-john.garry@huawei.com> <055f5ee8-4905-c229-0e33-6379cf65dfbc@nokia.com> CC: Alexander Sverdlin , , , , , , , , From: John Garry Message-ID: <2064e8da-d0da-6d55-e700-af3f428b348d@huawei.com> Date: Mon, 17 Sep 2018 15:55:20 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <055f5ee8-4905-c229-0e33-6379cf65dfbc@nokia.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.41] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/08/2018 19:21, Alexander Sverdlin wrote: > Hello John! > Hi Greg, Can you kindly consider picking up this patch? It still applies to the branches today in your tty git, but let me know if you still rather I resend. Thanks, John > On 30/08/2018 11:08, John Garry wrote: >> In commit c58caaab3bf8 ("serial: 8250: of: Defer probe on missing IRQ"), a >> check was added for the UART driver being probed prior to the parent IRQ >> controller. >> >> Unfortunately this breaks certain boards which have no interrupt support, >> like Huawei D03. >> >> Indeed, the 8250 DT bindings state that interrupts should be supported - >> not must. >> >> To fix, switch from irq_of_parse_and_map() to of_irq_get(), which >> does relay whether the IRQ host controller domain is not ready, i.e. >> defer probe, instead of assuming it. >> >> Fixes: c58caaab3bf8 ("serial: 8250: of: Defer probe on missing IRQ") >> Signed-off-by: John Garry > > This indeed looks like a proper way to handle both cases: > > Reviewed-by: Alexander Sverdlin > Tested-by: Alexander Sverdlin > >> --- >> >> Change in v2: >> - fix check on irq value >> >> Note: I think that it would better if we could try to get the interrupt >> before clk+pm enabling, so we don't need to disable later when >> deferring, but this is not a fix. >> >> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c >> index af8beef..877fd7f 100644 >> --- a/drivers/tty/serial/8250/8250_of.c >> +++ b/drivers/tty/serial/8250/8250_of.c >> @@ -58,7 +58,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev, >> struct resource resource; >> struct device_node *np = ofdev->dev.of_node; >> u32 clk, spd, prop; >> - int ret; >> + int ret, irq; >> >> memset(port, 0, sizeof *port); >> >> @@ -143,21 +143,27 @@ static int of_platform_serial_setup(struct platform_device *ofdev, >> if (ret >= 0) >> port->line = ret; >> >> - port->irq = irq_of_parse_and_map(np, 0); >> - if (!port->irq) { >> - ret = -EPROBE_DEFER; >> - goto err_unprepare; >> + irq = of_irq_get(np, 0); >> + if (irq < 0) { >> + if (irq == -EPROBE_DEFER) { >> + ret = -EPROBE_DEFER; >> + goto err_unprepare; >> + } >> + /* IRQ support not mandatory */ >> + irq = 0; >> } >> >> + port->irq = irq; >> + >> info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL); >> if (IS_ERR(info->rst)) { >> ret = PTR_ERR(info->rst); >> - goto err_dispose; >> + goto err_unprepare; >> } >> >> ret = reset_control_deassert(info->rst); >> if (ret) >> - goto err_dispose; >> + goto err_unprepare; >> >> port->type = type; >> port->uartclk = clk; >> @@ -184,8 +190,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev, >> port->handle_irq = fsl8250_handle_irq; >> >> return 0; >> -err_dispose: >> - irq_dispose_mapping(port->irq); >> err_unprepare: >> clk_disable_unprepare(info->clk); >> err_pmruntime: >> >