From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 547A13C6BA for ; Tue, 4 Mar 2025 02:23:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741055002; cv=none; b=BjBoZ2rmZqcvXSKo6OM5VAmroPTxn1+i756AtWT6YokTTCM5i+URjTrnKl3AqpGBIrfKtptc0ieBW3nfIXhzbPCPOFsI6VgAACnErWJyGNZwGSB4WsZPlukt+CFIpG/I8pPHeKIs9v84qMFGfU4nHKxsbg1nA1yiBPAu84cBop4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741055002; c=relaxed/simple; bh=lTLe8as+VCR92Mx4madXaiO+ags5AfU9/UlYBjKlYgY=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=og4Af3Zaat+FiNflgGkBxEnMqTcFhfqUP0A7HqOMv6dfTrrNgwci6Sl51c/b2ZoCHOpf8Ba2W9/RSYQEeLi6pHX1jPlTbrYx7rQkfr3M97pnscVucUCVQUCVJeu5zZk8F/OZokcG+Qzm2rAIEfgZZe8iVq1gaZOZr5EZ0UyMv94= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.48]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Z6KF549xCzpbWH; Tue, 4 Mar 2025 10:21:45 +0800 (CST) Received: from kwepemd500013.china.huawei.com (unknown [7.221.188.12]) by mail.maildlp.com (Postfix) with ESMTPS id 779DF18009E; Tue, 4 Mar 2025 10:23:16 +0800 (CST) Received: from [10.159.166.136] (10.159.166.136) by kwepemd500013.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 4 Mar 2025 10:23:14 +0800 Message-ID: Date: Tue, 4 Mar 2025 10:23:14 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 drm-dp 7/8] drm/hisilicon/hibmc: Enable this hot plug detect of irq feature To: Dmitry Baryshkov CC: , , , , , , , , , , , , , , , , References: <5af62fa9-e71b-412f-8640-502f03fcaa52@huawei.com> <4hicem4rbz5l7wnzaaz3krrl3euh2dmvlah2rb7errrdq5fann@44dvdxirkuzh> <6506e448-3851-436f-9354-42f9ef844d27@huawei.com> <6e54c88f-dfaf-462d-b66b-c237d19faec6@huawei.com> From: Yongbang Shi In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemd500013.china.huawei.com (7.221.188.12) > On Mon, Mar 03, 2025 at 01:02:44PM +0800, Yongbang Shi wrote: >>> On Sat, 1 Mar 2025 at 11:54, Yongbang Shi wrote: >>>>> On Sat, Mar 01, 2025 at 04:45:40PM +0800, Yongbang Shi wrote: >>>>>>> On Thu, Feb 27, 2025 at 09:46:10PM +0800, Yongbang Shi wrote: >>>>>>>>> On Tue, Feb 25, 2025 at 09:57:17PM +0800, Yongbang Shi wrote: >>>>>>>>>>> On Mon, 24 Feb 2025 at 16:03, Yongbang Shi wrote: >>>>>>>>>>>>> On Sat, Feb 22, 2025 at 06:35:48PM +0800, Yongbang Shi wrote: >>>>>>>>>>>>>>>> +static int hibmc_dp_hpd_event(struct drm_client_dev *client) >>>>>>>>>>>>>>>> +{ >>>>>>>>>>>>>>>> + struct hibmc_dp *dp = container_of(client, struct hibmc_dp, client); >>>>>>>>>>>>>>>> + struct hibmc_drm_private *priv = to_hibmc_drm_private(dp->drm_dev); >>>>>>>>>>>>>>>> + struct drm_display_mode *mode = &priv->crtc.state->adjusted_mode; >>>>>>>>>>>>>>>> + int ret; >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> + if (dp->hpd_status) { >>>>>>>>>>>>>>>> + hibmc_dp_hpd_cfg(&priv->dp); >>>>>>>>>>>>>>>> + ret = hibmc_dp_prepare(dp, mode); >>>>>>>>>>>>>>>> + if (ret) >>>>>>>>>>>>>>>> + return ret; >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> + hibmc_dp_display_en(dp, true); >>>>>>>>>>>>>>>> + } else { >>>>>>>>>>>>>>>> + hibmc_dp_display_en(dp, false); >>>>>>>>>>>>>>>> + hibmc_dp_reset_link(&priv->dp); >>>>>>>>>>>>>>>> + } >>>>>>>>>>>>>>> If I understand this correctly, you are using a separate drm_client to >>>>>>>>>>>>>>> enable and disable the link & display. Why is it necessary? Existing >>>>>>>>>>>>>>> drm_clients and userspace compositors use drm framework, they should be >>>>>>>>>>>>>>> able to turn the display on and off as required. >>>>>>>>>>>>>>> >>>>>>>>>>>>>> Thanks for your asking, there are cfg/reset process when the connector 's pluging in/out. >>>>>>>>>>>>>> We want to cfg DP registers again when the connector changes. Not only dp link training, but also cfg >>>>>>>>>>>>>> the different video modes into DP registers. >>>>>>>>>>>>> Why? The link training and mode programming should happen during >>>>>>>>>>>>> pre_enable / enable stage (legacy or atomic). >>>>>>>>>>>> Hi Dmitry, >>>>>>>>>>>> >>>>>>>>>>>> Right, that's what I'm curious about. It won't call encoder enble/disable functions when I triggered HPD. >>>>>>>>>>>> And I'm sure the drm_connector_helper_hpd_irq_event() is called. So I add a drm_client for it.I >>>>>>>>>>> It should be userspace, who triggers the enable/disable (or it should >>>>>>>>>>> be the in-kernel fbdev / fbcon, which interface through the generic >>>>>>>>>>> drm_fbdev client). >>>>>>>>>> Right, I knew it. When I insmode my driver firstly (or restart display service), it will call disable, modeset and enable, >>>>>>>>>> by user, but it won't call when HPD triggered . >>>>>>>>> - Is HPD even properly delivered to userspace? What kind of compsitor >>>>>>>>> are you using? Is .detect working properly and reporting a correct >>>>>>>>> plug-in state? >>>>>>>> Thanks for your answering. I'm not very good understanding about userspace in framework. In my opinion, when I call >>>>>>>> this drm_connector_helper_hpd_irq_event(), the HPD will deliver to userspace. >>>>>>>> I use Xorg, and the display service is GDM. >>>>>>>> The .detect is called and the getting modes info is correct. >>>>>>>> I find that it would only trigger(disable, modeset and enable), when I changed resolutions, restart display service and insmod driver. >>>>>>> You can go to the display settings in GDM. It would be interesting to >>>>>>> observe if it notes the second monitor or not. Last, but not least, you >>>>>>> can use a simple tool like 'xrandr' under your XOrg session to set the >>>>>>> display resolution. >>>>>> Thank you for your advice! >>>>>> Right, there are DP and VGA two monitors. I tried to totally remove the vga connector in driver, the problem is gone. >>>>>> So do I need to clear the vga connector, if dp is plugged in? >>>>> Unless your hardware can not manage two outputs at the same time, no, >>>>> you don't have to. Just check how it behaves on x86 systems. Ideally >>>>> your driver should have the same behaviour. >>>> Our hardware cannot support two outputs with different timing, so I used the one crtc and one plane that DP and VGA share. And just add a new DP connector >>>> with a encoder, just like the previous VGA's code logic. But the HPD problem makes me feel confused, should I change the framwork structure to slove this problem? >>> I think registering a single CRTC is a correct way. Then it is logical >>> that there is no mode set on the DP when you connect it. The userspace >>> can not output any data. However if you disconnect VGA and connect DP >>> then it should become active and should output your desktop >>> environment. >> Okay, Thank you for your guidance. So I need to disconnect VGA when I get the HPD (plugged in) , then >> userapce will active and enanble DP, right? > Yes. I'm sorry for that, just wanna make sure one more thing. I found if I only set the VGA connector's status to disconnected when HPD plugged in, it won't be active. And If I add drm_cleanup_connector() for VGA, it work. So is this okay that I use this cleanup in HPD? >> >>>> And also, I will check whether this driver works good on the x86 server. Right now, I'm testing on arm64 server. >>>> >>>>>> And also, I used xrandr to set modes after 'startx'. Changing resolutions works, >>>>>> but there are errs when set some low resolutions. >>>>> That's a separate topic, most likely related to timing or to some other >>>>> issues. You can fix that separately (but please do, switching modes >>>>> should work). >>>> Okay! >>>> >>>>