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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY 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 2507CC43381 for ; Wed, 20 Mar 2019 06:48:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED6262184D for ; Wed, 20 Mar 2019 06:48:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727362AbfCTGsP (ORCPT ); Wed, 20 Mar 2019 02:48:15 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:24802 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726169AbfCTGsP (ORCPT ); Wed, 20 Mar 2019 02:48:15 -0400 X-UUID: 7e1cab0520674881afbe688c90c5af3b-20190320 X-UUID: 7e1cab0520674881afbe688c90c5af3b-20190320 Received: from mtkcas06.mediatek.inc [(172.21.101.30)] by mailgw02.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 909345915; Wed, 20 Mar 2019 14:47:59 +0800 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs05n1.mediatek.inc (172.21.101.15) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 20 Mar 2019 14:47:57 +0800 Received: from [172.21.77.4] (172.21.77.4) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Wed, 20 Mar 2019 14:47:57 +0800 Message-ID: <1553064478.28297.3.camel@mtksdaap41> Subject: Re: [PATCH] gpu/drm: mediatek: call mtk_dsi_stop() after mtk_drm_crtc_atomic_disable() From: CK Hu To: Hsin-Yi Wang CC: , Philipp Zabel , David Airlie , Daniel Vetter , Matthias Brugger , , , Date: Wed, 20 Mar 2019 14:47:58 +0800 In-Reply-To: References: <20190318040915.101218-1-hsinyi@chromium.org> <1553051356.20221.23.camel@mtksdaap41> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Hsin-yi: On Wed, 2019-03-20 at 13:39 +0800, Hsin-Yi Wang wrote: > On Wed, Mar 20, 2019 at 11:09 AM CK Hu wrote: > > > > Hi, Hsin-yi: > > > > On Mon, 2019-03-18 at 12:09 +0800, Hsin-Yi Wang wrote: > > > mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(), which needs > > > ovl irq for drm_crtc_wait_one_vblank(), since after mtk_dsi_stop() is called, > > > ovl irq will be disabled. If drm_crtc_wait_one_vblank() is called after last > > > irq, it will timeout with this message: "vblank wait timed out on crtc 0". This > > > happens sometimes when turning off the screen. > > > > > > In drm_atomic_helper.c#disable_outputs(), > > > the calling sequence when turning off the screen is: > > > > > > 1. mtk_dsi_encoder_disable() > > > --> mtk_output_dsi_disable() > > > --> mtk_dsi_stop(); // sometimes make vblank timeout in atomic_disable > > > --> mtk_dsi_poweroff(); > > > 2. mtk_drm_crtc_atomic_disable() > > > --> drm_crtc_wait_one_vblank(); > > > ... > > > --> mtk_dsi_ddp_stop() > > > --> mtk_dsi_poweroff(); > > > > > > > Thanks for your inference, but I wonder this patch meet all > > consideration. In MT8173 with a bridge chip, the timing to disable dsi > > signal output would influence bridge chip output garbage or not. It's > > better that you could test this on MT8173, or let this patch go for > > weeks and wait for someone to test. If no one care about MT8173, I could > > accept this patch. > We care about MT8173, but it's not easy to test since we have to bring > the whole kernel to >= 4.19 to be able to test latest dsi driver. > The patch (0707632b5bac) that added mtk_dsi_stop() was after MT8173 > (on 3.18), for panel without bridge, so I think without mtk_dsi_stop() > was also working fine for MT8173. OK, I find that in the first version of this driver, there is no mtk_dsi_stop() before mtk_dsi_poweroff(), so I think MT8173 does not do mtk_dsi_stop(). So maybe this works fine for MT8173. Regards, CK > > > > > > Change to make mtk_dsi_stop() called in mtk_dsi_ddp_stop() instead of > > > mtk_output_dsi_disable(). > > > > mtk_dsi_poweroff() has reference count, why not just move mtk_dsi_stop() > > into mtk_dsi_poweroff()? > Yes, we can also call mtk_dsi_stop() in mtk_dsi_poweroff() when > refcount is 0. I can send v2 if you think this way is better. > > Thanks > > > > Regards, > > CK > > > > > > > > Fixes: 0707632b5bac ("drm/mediatek: update DSI sub driver flow for sending commands to panel") > > > Signed-off-by: Hsin-Yi Wang > > > --- > > > drivers/gpu/drm/mediatek/mtk_dsi.c | 4 +++- > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > > > index b00eb2d2e086..cdd9637dd517 100644 > > > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > > > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > > > @@ -696,7 +696,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi) > > > } > > > } > > > > > > - mtk_dsi_stop(dsi); > > > mtk_dsi_poweroff(dsi); > > > > > > dsi->enabled = false; > > > @@ -857,6 +856,7 @@ static void mtk_dsi_ddp_stop(struct mtk_ddp_comp *comp) > > > { > > > struct mtk_dsi *dsi = container_of(comp, struct mtk_dsi, ddp_comp); > > > > > > + mtk_dsi_stop(dsi); > > > mtk_dsi_poweroff(dsi); > > > } > > > > > > @@ -1178,6 +1178,8 @@ static int mtk_dsi_remove(struct platform_device *pdev) > > > struct mtk_dsi *dsi = platform_get_drvdata(pdev); > > > > > > mtk_output_dsi_disable(dsi); > > > + mtk_dsi_stop(dsi); > > > + mtk_dsi_poweroff(dsi); > > > component_del(&pdev->dev, &mtk_dsi_component_ops); > > > > > > return 0; > > > >