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, URIBL_BLOCKED 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 83D71C43381 for ; Fri, 22 Mar 2019 01:21:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5151521900 for ; Fri, 22 Mar 2019 01:21:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727490AbfCVBVn (ORCPT ); Thu, 21 Mar 2019 21:21:43 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:37559 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727397AbfCVBVn (ORCPT ); Thu, 21 Mar 2019 21:21:43 -0400 X-UUID: 82716ddd024649f3bf5b6f907ffea631-20190322 X-UUID: 82716ddd024649f3bf5b6f907ffea631-20190322 Received: from mtkmrs01.mediatek.inc [(172.21.131.159)] by mailgw02.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 1919452019; Fri, 22 Mar 2019 09:21:37 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs05n2.mediatek.inc (172.21.101.140) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 22 Mar 2019 09:21:35 +0800 Received: from [172.21.77.4] (172.21.77.4) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Fri, 22 Mar 2019 09:21:35 +0800 Message-ID: <1553217695.25217.5.camel@mtksdaap41> Subject: Re: [PATCH v2] 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: Fri, 22 Mar 2019 09:21:35 +0800 In-Reply-To: References: <20190320071825.20268-1-hsinyi@chromium.org> <1553131722.18216.10.camel@mtksdaap41> <1553132815.18216.18.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 Thu, 2019-03-21 at 22:09 +0800, Hsin-Yi Wang wrote: > On Thu, Mar 21, 2019 at 9:46 AM CK Hu wrote: > > > > Hi, Hsin-yi: > > > > On Thu, 2019-03-21 at 09:28 +0800, CK Hu wrote: > > > Hi, Hsin-yi: > > > > > > On Wed, 2019-03-20 at 15:18 +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(); > > > > > > > > mtk_dsi_poweroff() has reference count design, change to make mtk_dsi_stop() > > > > called in mtk_dsi_poweroff() when refcount is 0. > > > > > > > > Fixes: 0707632b5bac ("drm/mediatek: update DSI sub driver flow for sending commands to panel") > > > > Signed-off-by: Hsin-Yi Wang > > > > --- > > > > change log: > > > > v1->v2: > > > > * update commit message. > > > > * call mtk_dsi_stop() in mtk_dsi_poweroff() when refcount is 0. > > > > --- > > > > drivers/gpu/drm/mediatek/mtk_dsi.c | 5 ++++- > > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > > > > index b00eb2d2e086..e152f37af57d 100644 > > > > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > > > > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > > > > @@ -630,6 +630,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) > > > > if (--dsi->refcount != 0) > > > > return; > > > > > > > > + mtk_dsi_stop(dsi); > > > > + > > > > if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) { > > > > if (dsi->panel) { > > > > if (drm_panel_unprepare(dsi->panel)) { > > > > > > I think you just move mtk_dsi_stop() into mtk_dsi_poweroff() would works > > > fine, but I would rather like calling mtk_dsi_start() and mtk_dsi_stop() > > > in a symmetric manner. That means you may also move below functions into > > > mtk_dsi_poweron(): > > > > > > mtk_dsi_set_mode(dsi); > > > mtk_dsi_clk_hs_mode(dsi, 1); > > > mtk_dsi_start(dsi); > > For MT8183 with bridge panel, calling mtk_dsi_start() in > mtk_dsi_poweron() when refcount is 0->1, like the following order, > will results in no irq, not sure why though. I think this might be the > timing issue you mentioned in patch v1. (MT8183 without bridge panel > doesn't have this issue.) > > atomic_enable > --> mtk_crtc_ddp_hw_init > --> mtk_dsi_ddp_start > --> mtk_dsi_poweron (ref 0->1) > --> drm_panel_prepare > --> *mtk_dsi_start // results in no irq for MT8183 with bridge > --> drm_crtc_vblank_on > > mtk_output_dsi_enable > --> mtk_dsi_poweron (ref 1->2, ignored) > --> mtk_dsi_start //original position > > For mtk_dsi_stop() both with or without bridge is fine. I'm not familiar with dsi hardware, so I could not answer why this problem happen. Jitao is familiar with dsi hardware, you may ask him for help. If this is hardware behavior, I could accept asymmetric flow, but please be sure this is hardware behavior not software bug. Regards, CK > > > > > > > > > > > @@ -696,7 +698,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi) > > > > } > > > > } > > > > > > > > - mtk_dsi_stop(dsi); > > > > mtk_dsi_poweroff(dsi); > > > > > > > > dsi->enabled = false; > > > > @@ -1178,6 +1179,8 @@ 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); > > > > > > I think mtk_output_dsi_disable() would call mtk_dsi_poweroff(), and > > > mtk_dsi_poweroff() would call mtk_dsi_stop(), so these two line are > > > redundant. And I think you should remove mtk_dsi_stop() in > > > mtk_output_dsi_disable(), why not in this patch? > > > > You've removed mtk_dsi_stop() in mtk_output_dsi_disable(), I just miss > > it, sorry for this. > > > > Regards, > > CK > > > > > > > > Regards, > > > CK > > > > > > > component_del(&pdev->dev, &mtk_dsi_component_ops); > > > > > > > > return 0; > > > > > > >