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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 39B23C433E0 for ; Tue, 16 Mar 2021 06:19:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAD2765055 for ; Tue, 16 Mar 2021 06:19:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229867AbhCPGSt (ORCPT ); Tue, 16 Mar 2021 02:18:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229811AbhCPGSs (ORCPT ); Tue, 16 Mar 2021 02:18:48 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22337C061756 for ; Mon, 15 Mar 2021 23:18:48 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id d23so13239322plq.2 for ; Mon, 15 Mar 2021 23:18:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=TguaXqmd8x2or75hALM9SNABakfsKUxz8lHQoAaEArU=; b=Mj4QyqhV3XdiAqA4SjpUsa5Tq5JsJWiCZkqHI6b+KDlrVz8tR2Nsy1lhorqh9/sxcG BQfxwsPZrge3xBoS6WdenSEkCx4/tQS1+wGVfMzng/SjMAs4C8zvEJJGwtIVXpK5yj7m j69KRo6wN7A7qXntRCEpDF1RhN5cvRe5SwjAazXBw/4O4K6ITDjcfhbpzicbsNCYXQwE EzIo177kEKnibzH2Rxt3YoHtwetg+XjFUnUKW/BYSpCGn22bo8HIKLAlJ+N10Ndh0R4E bAgEsoQYuiye/ih5jS+yz6tzYokPqycjCXOqkolf+o6gKpEvG0Qk9rS6aSVwQ4+zKoCx iYUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=TguaXqmd8x2or75hALM9SNABakfsKUxz8lHQoAaEArU=; b=EOPMhPgMotnUrxCPS2EbgfZK/IUTTRGzuMldduqRU586A3mOzd7BgnByDp1tRyEssv lgzJGxV00ixSpCGt5UANPXOgsRLI9WSb0G4gcdRXIERMFOTnij8kCdyBX9A8VHKUWWb4 gNldv1SL0FPU79Q4nmiYPQkV3PaVAWjFUuzqy6uVhVZ5ytQjArj+PDcr9A/aUU3kx798 bgIN1+ZFiDcBUghEdkpJ1xkG626zWL+RYHfMtA4VP/JLWFncidnnM+bzSh4y9YFVNPvC qNFMN1DKosbVMaGMkxTjL+594uT8Fz22ipyGv/dtW4HVHf7FhpyFdaRry1Hp/ETp50wu E3hg== X-Gm-Message-State: AOAM5300uW8OZX0CwYfVo4Es2y/UkPoHB86e/koidEntCNnASnBRX7Wc VP5FQlvaurcBy2qSg5DMrud3 X-Google-Smtp-Source: ABdhPJyPt9iAovD241Wypbx2549tYfVbiI0PbF3mXX5I55qXsahZMaDBSmHXsW27iSbo9uUtYYHiyQ== X-Received: by 2002:a17:90a:8a8b:: with SMTP id x11mr3144751pjn.151.1615875527679; Mon, 15 Mar 2021 23:18:47 -0700 (PDT) Received: from thinkpad ([103.66.79.72]) by smtp.gmail.com with ESMTPSA id v3sm14865198pff.217.2021.03.15.23.18.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Mar 2021 23:18:47 -0700 (PDT) Date: Tue, 16 Mar 2021 11:48:43 +0530 From: Manivannan Sadhasivam To: Jeffrey Hugo Cc: hemantk@codeaurora.org, bbhatt@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] bus: mhi: core: Check state before processing power_down Message-ID: <20210316061843.GI1798@thinkpad> References: <1615409365-8165-1-git-send-email-jhugo@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1615409365-8165-1-git-send-email-jhugo@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Wed, Mar 10, 2021 at 01:49:25PM -0700, Jeffrey Hugo wrote: > We cannot process a power_down if the power state is DISABLED. There is > no valid mhi_ctxt in that case, so attepting to process the power_down > will likely result in a null pointer dereference. If the power state is > DISABLED, there is nothing to do anyways, so just bail early. > > Signed-off-by: Jeffrey Hugo Applied to mhi-next! Thanks, Mani > --- > > v3: Move the pm_lock use up > v2: Fix subject and tweak the locking to avoid needless lock/unlock/relock > > drivers/bus/mhi/core/pm.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c > index 414da4f..ea62549 100644 > --- a/drivers/bus/mhi/core/pm.c > +++ b/drivers/bus/mhi/core/pm.c > @@ -1149,6 +1149,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl) > mhi_deinit_dev_ctxt(mhi_cntrl); > > error_dev_ctxt: > + mhi_cntrl->pm_state = MHI_PM_DISABLE; > mutex_unlock(&mhi_cntrl->pm_mutex); > > return ret; > @@ -1160,12 +1161,19 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) > enum mhi_pm_state cur_state, transition_state; > struct device *dev = &mhi_cntrl->mhi_dev->dev; > > + mutex_lock(&mhi_cntrl->pm_mutex); > + write_lock_irq(&mhi_cntrl->pm_lock); > + cur_state = mhi_cntrl->pm_state; > + if (cur_state == MHI_PM_DISABLE) { > + write_unlock_irq(&mhi_cntrl->pm_lock); > + mutex_unlock(&mhi_cntrl->pm_mutex); > + return; /* Already powered down */ > + } > + > /* If it's not a graceful shutdown, force MHI to linkdown state */ > transition_state = (graceful) ? MHI_PM_SHUTDOWN_PROCESS : > MHI_PM_LD_ERR_FATAL_DETECT; > > - mutex_lock(&mhi_cntrl->pm_mutex); > - write_lock_irq(&mhi_cntrl->pm_lock); > cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state); > if (cur_state != transition_state) { > dev_err(dev, "Failed to move to state: %s from: %s\n", > -- > Qualcomm Technologies, Inc. is a member of the > Code Aurora Forum, a Linux Foundation Collaborative Project. >