Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751979AbbHTICz (ORCPT ); Thu, 20 Aug 2015 04:02:55 -0400 Received: from regular1.263xmail.com ([211.150.99.140]:35482 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbbHTICu (ORCPT ); Thu, 20 Aug 2015 04:02:50 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: ykk@rock-chips.com X-FST-TO: linux-arm-kernel@lists.infradead.org X-SENDER-IP: 191.101.57.25 X-LOGIN-NAME: ykk@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Message-ID: <55D58993.4060502@rock-chips.com> Date: Thu, 20 Aug 2015 03:02:27 -0500 From: Yakir Yang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Jingoo Han CC: Heiko Stuebner , Thierry Reding , Fabio Estevam , Inki Dae , "joe@perches.com" , Russell King , "djkurtz@google.com" , "dianders@google.com" , "seanpaul@google.com" , Takashi Iwai , "ajaynumb@gmail.com" , Andrzej Hajda , Kyungmin Park , Philipp Zabel , David Airlie , Gustavo Padovan , Vincent Palatin , Mark Yao , Andy Yan , Kumar Gala , Ian Campbell , Rob Herring , Pawel Moll , Kishon Vijay Abraham I , "dri-devel@lists.freedesktop.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-samsung-soc@vger.kernel.org" , "linux-rockchip@lists.infradead.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH v3 12/14] drm: bridge/analogix_dp: expand the delay time for hpd detect References: <1439995728-18046-1-git-send-email-ykk@rock-chips.com> <1439995929-18719-1-git-send-email-ykk@rock-chips.com> In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2539 Lines: 71 Hi Jingoo, On 08/20/2015 01:11 AM, Jingoo Han wrote: > On 2015. 8. 19., at PM 11:52, Yakir Yang wrote: >> Some edp screen with no hpd signal would need some delay time >> to ensure that screen would be ready for work, so we can expand >> the delay time in hpd detect function, it works prefectly on my >> rk3288 sdk board. > Then, this delay has a dependency on the "rk3288 sdk" board. > Also, if the delay time is expanded, the booting time of some Exybos boards will be increased unnecessarily. :-( > > So, please add new DT property such as 'hpd-delay' that can be added to board DT files. > > If there is not that DT property in DT files, the default value '10' will written to a variable such as 'unsigned int hpd_delay'. > If there is the DT property in DT files, the delay value will written to the variable when parsing DT values > and will be used in analogix_dp_detect_hpd(). > > What I want to say is that there should not be harmful effect on the existing Exynos boards, due to unrelated reasons. Yeah, you are right, I made an mistake here. And I want to put this delay to "need-force-hpd" code, cause this property is for the no-hpd-signal eDP screen. But strangely, with my this series, I don't need the expand delay any more, I am not sure which change improved this, I guess those delay time should come from drm core ? Whatever seems we don't need this delay for now, and if I can find the exact reason and realize I still need this delay, I prefer to add those delay in "need-force-hpd" code. Thanks, - Yakir > Best regards, > Jingoo Han > >> Signed-off-by: Yakir Yang >> --- >> Changes in v3: None >> Changes in v2: None >> >> drivers/gpu/drm/bridge/analogix_dp_core.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/bridge/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix_dp_core.c >> index 99870f7..75dd44a 100644 >> --- a/drivers/gpu/drm/bridge/analogix_dp_core.c >> +++ b/drivers/gpu/drm/bridge/analogix_dp_core.c >> @@ -68,7 +68,7 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp) >> return 0; >> >> timeout_loop++; >> - usleep_range(10, 11); >> + usleep_range(100, 110); >> } >> >> /* >> -- >> 1.9.1 >> >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/