From nobody Sun Dec 14 06:16:08 2025 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 165C1C00140 for ; Mon, 15 Aug 2022 20:02:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241444AbiHOUCe (ORCPT ); Mon, 15 Aug 2022 16:02:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345921AbiHOUA7 (ORCPT ); Mon, 15 Aug 2022 16:00:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9ACB7A51D; Mon, 15 Aug 2022 11:53:27 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 9AD70B810A0; Mon, 15 Aug 2022 18:53:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07DADC433D7; Mon, 15 Aug 2022 18:53:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589604; bh=gSo018KO7yciQS/cs61HZj9oE5g4mjzMJegIb32bSyo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gSAdD2kACO7rTuxfMGzgeUMwm5tWDrswNP342T4DPStdBeRTqG+4MiHrGpvN0zHdP 8Pl1Ny13LGH70LboPFNpdjVqG+f4fNL1K10KPwBNN5lAQ7cOzrREERzgNGrSNLUyWb ZfsKlUnnr+dzpf+++5Tv8CC3yBInidhgvBjseoVo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rob Clark Subject: [PATCH 5.15 771/779] drm/msm: Fix dirtyfb refcounting Date: Mon, 15 Aug 2022 20:06:55 +0200 Message-Id: <20220815180410.350724076@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Rob Clark commit 9225b337072a10bf9b09df8bf281437488dd8a26 upstream. refcount_t complains about 0->1 transitions, which isn't *quite* what we wanted. So use dirtyfb=3D=3D1 to mean that the fb is not connected to any output that requires dirtyfb flushing, so that we can keep the underflow and overflow checking. Fixes: 9e4dde28e9cd ("drm/msm: Avoid dirtyfb stalls on video mode displays = (v2)") Signed-off-by: Rob Clark Link: https://lore.kernel.org/r/20220304202146.845566-1-robdclark@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/msm/msm_fb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/msm/msm_fb.c +++ b/drivers/gpu/drm/msm/msm_fb.c @@ -37,7 +37,7 @@ static int msm_framebuffer_dirtyfb(struc /* If this fb is not used on any display requiring pixel data to be * flushed, then skip dirtyfb */ - if (refcount_read(&msm_fb->dirtyfb) =3D=3D 0) + if (refcount_read(&msm_fb->dirtyfb) =3D=3D 1) return 0; =20 return drm_atomic_helper_dirtyfb(fb, file_priv, flags, color, @@ -221,6 +221,8 @@ static struct drm_framebuffer *msm_frame goto fail; } =20 + refcount_set(&msm_fb->dirtyfb, 1); + drm_dbg_state(dev, "create: FB ID: %d (%p)", fb->base.id, fb); =20 return fb;