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 133EDC433F5 for ; Wed, 9 Feb 2022 22:03:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234842AbiBIWDg (ORCPT ); Wed, 9 Feb 2022 17:03:36 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:48280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234866AbiBIWDW (ORCPT ); Wed, 9 Feb 2022 17:03:22 -0500 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95135DF498A3 for ; Wed, 9 Feb 2022 14:03:24 -0800 (PST) Received: by mail-lf1-x135.google.com with SMTP id u6so6858580lfc.3 for ; Wed, 09 Feb 2022 14:03:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=m/jM298Q2lilwuRAcB9szC9CfZcuho3/psKjLfOmipk=; b=TBVPofOcDZHSNsfDSrK9N25wXlUqmiOwgAkzkjmAX7pRNqnzIlCv+Yazw38kCracB1 PfVDsmtnw7AZxa6Rvn5RueZwpXPFbDHYD7wl8veFe5kS1uzo3pW+Q54NcX6wK7F4ifN9 kCIpFQOmGPlWeI+F+Daz9XRNW0Np/b/ccFxBcKS7/6U+f2704dO9X6NRZidd5HhbDpDO jDr5wylLX3hFKJ2e6jweRbE0x4iGflbnv4rwQe6jxf7pTSNFufATUiEHoKNdn4H37ZiU l2QWN6u7oLNWiu3x7fhNSVxYWqN2s67IOWxnFQ+cHgpG4/KqiJottk6xQuvfFpjx+4zG p3KA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=m/jM298Q2lilwuRAcB9szC9CfZcuho3/psKjLfOmipk=; b=VZTFXm6pXH/DhAkxbnyJL0eJQFfr/ar/ZENSkqJEAe/PtQvegYynfNmct0Ex2c/r8B j/T0RK1xWroYKLD09pZECs3hO9wDHM4CmbhuIt0AwwqugifIFyUZw1isaCu/VskyIUx0 dUTG7Jn3tiLbgy3ZViKFGdgbrZQYD73kCLx4lTLtg/LS/tnf83EShwVApR6hJszOd4ac bhAaq0ZciJbORbcJYL0hZB/Ms+n+tXwieWrNvqQxZ002x/twRZdT9eYDOrKN64O5Q9XV re9CCifhYsUeZaqBvPfQr01ImXfGc7nLut8P7m5uJ6+2AYEBC/3nXdHKcP0UML/BD7Zr DnbQ== X-Gm-Message-State: AOAM530q8ostBEzF0KtZCki8AiVJPO2Y4HPapxW7ywdf4nau4FvoPLzc nw6owFJdjR0C0gNjqYMFW2+t8w== X-Google-Smtp-Source: ABdhPJxwEImBidIbwgxkjiktuZ2LvjO6+doHOTUKPtcJPGxnGqzJVQKkxUsjyj77e/ZRZY8CKdu1Dg== X-Received: by 2002:a05:6512:3a93:: with SMTP id q19mr3041722lfu.487.1644444202900; Wed, 09 Feb 2022 14:03:22 -0800 (PST) Received: from [192.168.1.211] ([37.153.55.125]) by smtp.gmail.com with ESMTPSA id a27sm2541809lfg.140.2022.02.09.14.03.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Feb 2022 14:03:22 -0800 (PST) Message-ID: <32259670-1261-a305-2bcb-57ebde792f24@linaro.org> Date: Thu, 10 Feb 2022 01:03:21 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 Subject: Re: [PATCH v2 2/2] drm/msm/hdmi: Remove spurious IRQF_ONESHOT flag Content-Language: en-GB To: Daniel Thompson , Rob Clark , Sean Paul , Abhinav Kumar Cc: David Airlie , Daniel Vetter , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20220201174734.196718-1-daniel.thompson@linaro.org> <20220201174734.196718-3-daniel.thompson@linaro.org> From: Dmitry Baryshkov In-Reply-To: <20220201174734.196718-3-daniel.thompson@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/02/2022 20:47, Daniel Thompson wrote: > Quoting the header comments, IRQF_ONESHOT is "Used by threaded interrupts > which need to keep the irq line disabled until the threaded handler has > been run.". When applied to an interrupt that doesn't request a threaded > irq then IRQF_ONESHOT has a lesser known (undocumented?) side effect, > which it to disable the forced threading of irqs. For "normal" kernels > if there is no thread_fn then IRQF_ONESHOT is a nop. > > In this case disabling forced threading is not appropriate because the > driver calls wake_up_all() (via msm_hdmi_i2c_irq) and also directly uses > the regular spinlock API for locking (in msm_hdmi_hdcp_irq() ). Neither > of these APIs can be called from no-thread interrupt handlers on > PREEMPT_RT systems. > > Fix this by removing IRQF_ONESHOT. > > Signed-off-by: Daniel Thompson Reviewed-by: Dmitry Baryshkov > --- > drivers/gpu/drm/msm/hdmi/hdmi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c > index 719720709e9e7..e167817b42958 100644 > --- a/drivers/gpu/drm/msm/hdmi/hdmi.c > +++ b/drivers/gpu/drm/msm/hdmi/hdmi.c > @@ -306,7 +306,7 @@ int msm_hdmi_modeset_init(struct hdmi *hdmi, > } > > ret = devm_request_irq(&pdev->dev, hdmi->irq, > - msm_hdmi_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, > + msm_hdmi_irq, IRQF_TRIGGER_HIGH, > "hdmi_isr", hdmi); > if (ret < 0) { > DRM_DEV_ERROR(dev->dev, "failed to request IRQ%u: %d\n", -- With best wishes Dmitry