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 86357C4332F for ; Mon, 7 Nov 2022 11:23:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231607AbiKGLXC (ORCPT ); Mon, 7 Nov 2022 06:23:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231494AbiKGLW4 (ORCPT ); Mon, 7 Nov 2022 06:22:56 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63322183B9; Mon, 7 Nov 2022 03:22:56 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id DD4A460FD8; Mon, 7 Nov 2022 11:22:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BBA1C433C1; Mon, 7 Nov 2022 11:22:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667820175; bh=yUKZRtowNMMbVtTq5rXqMDPbXb2eaKZkJ8OtKwKaqY4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WVIz9iZwbx1D1kS7/XKaNX8EVf5/TIRnYJDlbh8dWbof4KT5/xb79iMi9dMWCu0kE q/kfoU6uOSe/7IaF077huJ47i0IIwTqYp82F/jeTlJ7C5W0O6ejGpEsFvRhHXsNkfw Caff0Ts5H3gJOtklaH2yB9YTlPD7b3CS14mhuw4/3EDTm/vaZaSUrAtPJWVbdUOmYL Ba457wQCA96L7z9UFe6f496PJErZ0A/L+tdZmeTbSjl5clmXEZdLOxTvMMuUom8B9i HDtqXGZ2wDPi4r5Mju2oyZCVBfQ4SqNaGPAvXRRKaEqEqMM9DiaQjmChS1B0Ux/zKJ i2iojShGSt9mg== Date: Mon, 7 Nov 2022 16:52:43 +0530 From: Manivannan Sadhasivam To: Qiang Yu Cc: mani@kernel.org, loic.poulain@linaro.org, mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, quic_cang@quicinc.com, mrana@quicinc.com Subject: Re: [PATCH] bus: mhi: host: Disable preemption while processing data events Message-ID: <20221107112243.GA2220@thinkpad> References: <1667462111-55496-1-git-send-email-quic_qianyu@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1667462111-55496-1-git-send-email-quic_qianyu@quicinc.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 03, 2022 at 03:55:11PM +0800, Qiang Yu wrote: > If data processing of an event is scheduled out because core > is busy handling multiple irqs, this can starves the processing s/starves/starve > of MHI M0 state change event on another core. Fix this issue by > disabling irq on the core processing data events. > > Signed-off-by: Qiang Yu > --- > drivers/bus/mhi/host/main.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c > index f3aef77a..b58698d 100644 > --- a/drivers/bus/mhi/host/main.c > +++ b/drivers/bus/mhi/host/main.c > @@ -1027,13 +1027,14 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl, > > void mhi_ev_task(unsigned long data) > { > + unsigned long flags; > struct mhi_event *mhi_event = (struct mhi_event *)data; > struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl; > > /* process all pending events */ > - spin_lock_bh(&mhi_event->lock); > + spin_lock_irqsave(&mhi_event->lock, flags); Please add a comment stating why we are disabling local IRQs here. This will help in understanding the code better. Thanks, Mani > mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX); > - spin_unlock_bh(&mhi_event->lock); > + spin_unlock_irqrestore(&mhi_event->lock, flags); > } > > void mhi_ctrl_ev_task(unsigned long data) > -- > 2.7.4 > > -- மணிவண்ணன் சதாசிவம்