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 3FEEBC433F5 for ; Thu, 17 Mar 2022 12:46:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233697AbiCQMsA (ORCPT ); Thu, 17 Mar 2022 08:48:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233690AbiCQMrz (ORCPT ); Thu, 17 Mar 2022 08:47:55 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9DB0114368; Thu, 17 Mar 2022 05:46:38 -0700 (PDT) X-UUID: 44fd6c30f71a49728e795696ef312435-20220317 X-UUID: 44fd6c30f71a49728e795696ef312435-20220317 Received: from mtkcas10.mediatek.inc [(172.21.101.39)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 58590688; Thu, 17 Mar 2022 20:46:34 +0800 Received: from mtkexhb02.mediatek.inc (172.21.101.103) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 17 Mar 2022 20:46:33 +0800 Received: from mtkcas10.mediatek.inc (172.21.101.39) by mtkexhb02.mediatek.inc (172.21.101.103) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 17 Mar 2022 20:46:31 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkcas10.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 17 Mar 2022 20:46:30 +0800 Message-ID: <07e040716fed3f1c3a15af698767dbe8f77308ea.camel@mediatek.com> Subject: Re: [PATCH v1, 1/1] drm/mediatek: fixup ovl vblank callback data null pointer issue From: Rex-BC Chen To: Yongqiang Niu , Chun-Kuang Hu CC: Rob Herring , Matthias Brugger , Philipp Zabel , "David Airlie" , Daniel Vetter , Jassi Brar , Fabien Parent , "Dennis YC Hsieh" , , , , , , , Hsin-Yi Wang Date: Thu, 17 Mar 2022 20:46:31 +0800 In-Reply-To: <20220314080808.29370-2-yongqiang.niu@mediatek.com> References: <20220314080808.29370-1-yongqiang.niu@mediatek.com> <20220314080808.29370-2-yongqiang.niu@mediatek.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2022-03-14 at 16:08 +0800, Yongqiang Niu wrote: > ovl vblank_cb_data will be null pointer when disable ovl > vblank > Hello Yongqiang, What issue do you encounter? Is it a timing issue? > Signed-off-by: Yongqiang Niu > --- > drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c > b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c > index 2146299e5f52..f3a450c0ef2d 100644 > --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c > +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c > @@ -113,7 +113,6 @@ void mtk_ovl_disable_vblank(struct device *dev) > struct mtk_disp_ovl *ovl = dev_get_drvdata(dev); > > ovl->vblank_cb = NULL; > - ovl->vblank_cb_data = NULL; IMO, this may be not a good solution. If this is a timing issue and you don't need to handle irq after disable vblank. I think you should handle ovl->vblank_cb_data == NULL in mtk_disp_ovl_irq_handler? If I am wrong, please correct me. Thanks. BRs, Rex > writel_relaxed(0x0, ovl->regs + DISP_REG_OVL_INTEN); > } >