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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 D7155C04AAC for ; Mon, 20 May 2019 21:07:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD928216B7 for ; Mon, 20 May 2019 21:07:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="nL//rSHE"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="ofhwcs4U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726566AbfETVHj (ORCPT ); Mon, 20 May 2019 17:07:39 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:41438 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726116AbfETVHj (ORCPT ); Mon, 20 May 2019 17:07:39 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 2A27160E5A; Mon, 20 May 2019 21:07:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1558386458; bh=sWncJZuhv8jI+fIBFRSxi31uAvCtEl1i4p1lxELRFRA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nL//rSHE6KjOz11WOppOfdg1BN3yl8ghHHVhz73xGsT+Lg4VWyhE04fiURkXgMd4/ AoXnudMM8SOnS/5QSYsw6qba8/ryRIuWNYjCgtHAjxC0YDcRSgQQY3ZrN+QgEq94RX z2VLyfl88VQK/YnQaQISymEp0VM5ucs888ManETM= Received: from jcrouse1-lnx.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jcrouse@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 8A6EF6087F; Mon, 20 May 2019 21:07:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1558386455; bh=sWncJZuhv8jI+fIBFRSxi31uAvCtEl1i4p1lxELRFRA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ofhwcs4UV5Eiw/8Yh2sbqC5v5RszTv9UDRERtPCyHv57GGfii7jR7FIpsvYfSI3ix 7jVVXO5LMVHUH3yFV1a9VAI0JM6M2qONikDtYrsbXg6mGqh2iLCBpBkFpu4r/iCpgb /vwVtw1JbtNGZAEDezrF4QMBKcOmKSbWzsZDeUyY= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 8A6EF6087F Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=jcrouse@codeaurora.org Date: Mon, 20 May 2019 15:07:32 -0600 From: Jordan Crouse To: Andrea Parri Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Rob Clark , Sean Paul , David Airlie , Daniel Vetter , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, "Paul E. McKenney" , Peter Zijlstra Subject: Re: [PATCH 1/4] drm/msm: Fix improper uses of smp_mb__{before,after}_atomic() Message-ID: <20190520210732.GF24137@jcrouse1-lnx.qualcomm.com> Mail-Followup-To: Andrea Parri , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Rob Clark , Sean Paul , David Airlie , Daniel Vetter , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, "Paul E. McKenney" , Peter Zijlstra References: <1558373038-5611-1-git-send-email-andrea.parri@amarulasolutions.com> <1558373038-5611-2-git-send-email-andrea.parri@amarulasolutions.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1558373038-5611-2-git-send-email-andrea.parri@amarulasolutions.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, May 20, 2019 at 07:23:55PM +0200, Andrea Parri wrote: > These barriers only apply to the read-modify-write operations; in > particular, they do not apply to the atomic_set() primitive. > > Replace the barriers with smp_mb()s. > > Fixes: b1fc2839d2f92 ("drm/msm: Implement preemption for A5XX targets") > Cc: stable@vger.kernel.org > Reported-by: "Paul E. McKenney" > Reported-by: Peter Zijlstra > Signed-off-by: Andrea Parri > Cc: Rob Clark > Cc: Sean Paul > Cc: David Airlie > Cc: Daniel Vetter > Cc: Jordan Crouse > Cc: linux-arm-msm@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org > Cc: freedreno@lists.freedesktop.org > Cc: "Paul E. McKenney" > Cc: Peter Zijlstra I'll go ahead and ack this - I'm not super clued in on atomic barriers, but this seems to be in the spirit of what we are trying to do to protect the atomic value. Rob can disagree, of course. Acked-by: Jordan Crouse > --- > drivers/gpu/drm/msm/adreno/a5xx_preempt.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c > index 3d62310a535fb..ee0820ee0c664 100644 > --- a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c > +++ b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c > @@ -39,10 +39,10 @@ static inline void set_preempt_state(struct a5xx_gpu *gpu, > * preemption or in the interrupt handler so barriers are needed > * before... > */ > - smp_mb__before_atomic(); > + smp_mb(); > atomic_set(&gpu->preempt_state, new); > /* ... and after*/ > - smp_mb__after_atomic(); > + smp_mb(); > } > > /* Write the most recent wptr for the given ring into the hardware */ > -- > 2.7.4 > -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project