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 F207DC47091 for ; Tue, 12 Apr 2022 09:28:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1390305AbiDLJYn (ORCPT ); Tue, 12 Apr 2022 05:24:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356171AbiDLIJI (ORCPT ); Tue, 12 Apr 2022 04:09:08 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2EF7DEEA for ; Tue, 12 Apr 2022 00:39:39 -0700 (PDT) X-UUID: 476df98acc14430c9712202fa00f6542-20220412 X-UUID: 476df98acc14430c9712202fa00f6542-20220412 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 1947215072; Tue, 12 Apr 2022 15:39:31 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 12 Apr 2022 15:39:30 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 12 Apr 2022 15:39:30 +0800 Message-ID: <152363cfcfe240f9249fb08f06442d2ab9286900.camel@mediatek.com> Subject: Re: [PATCH v4,4/4] drm/mediatek: Add pull-down MIPI operation in mtk_dsi_poweroff function From: Rex-BC Chen To: , , , , , CC: , , , , , Date: Tue, 12 Apr 2022 15:39:30 +0800 In-Reply-To: <1649644308-8455-5-git-send-email-xinlei.lee@mediatek.com> References: <1649644308-8455-1-git-send-email-xinlei.lee@mediatek.com> <1649644308-8455-5-git-send-email-xinlei.lee@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, 2022-04-11 at 10:31 +0800, xinlei.lee@mediatek.com wrote: > From: Xinlei Lee > > In the dsi_enable function, mtk_dsi_rxtx_control is to > pull up the MIPI signal operation. Before dsi_disable, > MIPI should also be pulled down by writing a register > instead of disabling dsi. > > If disable dsi without pulling the mipi signal low, the value of > the register will still maintain the setting of the mipi signal being > pulled high. > After resume, even if the mipi signal is not pulled high, it will > still > be in the high state. > > Signed-off-by: Jitao Shi > Signed-off-by: Xinlei Lee > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c > b/drivers/gpu/drm/mediatek/mtk_dsi.c > index 9ad6f08c8bfe..e35343357f90 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -676,6 +676,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) > mtk_dsi_reset_engine(dsi); > mtk_dsi_lane0_ulp_mode_enter(dsi); > mtk_dsi_clk_ulp_mode_enter(dsi); > + /* set the lane number as 0 to pull down mipi */ > + writel(0, dsi->regs + DSI_TXRX_CTRL); > > mtk_dsi_disable(dsi); > Reviewed-by: Rex-BC Chen