From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (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 E26DE18DB24 for ; Sat, 1 Mar 2025 09:54:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740822897; cv=none; b=Q6d+kmR7441gAeJTWgGvde/eQDth/1k64/qlWSWNFmFerYxI374GcjRWptt7OW745P4yLEY+NPHvFlImhXhGpIBFRSN6S7mhZWAPPxAoD45Ate6wD7ogMT8a0nPJPinbCBiZVt7041/5ThMsicmS7w+njPO7f2StNUr//CxHN1M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740822897; c=relaxed/simple; bh=bEYql0zQPHjCxQDY02zKN3OFGTIeyDkYzpEibA2Z42E=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=c2H61P/xcbuGh6phSnkxARDX8nScQqaNLTjd/2ko0KVAyIAduOOcFM+ruwDFoMs/ONpd/FjuQ+Y+eYYmN65iTkvKES7rfe3U1YsHUf/FJflJn5/mi2q5TLPWgPJGNZhR51eL445uuRWa+fgNyeu0HodqeaLChwk47aNv80usb0A= 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=45.249.212.190 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 [172.19.88.163]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Z4gLV3xfGz2CprZ; Sat, 1 Mar 2025 17:50:42 +0800 (CST) Received: from kwepemd500013.china.huawei.com (unknown [7.221.188.12]) by mail.maildlp.com (Postfix) with ESMTPS id 0ED81180044; Sat, 1 Mar 2025 17:54:50 +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; Sat, 1 Mar 2025 17:54:48 +0800 Message-ID: Date: Sat, 1 Mar 2025 17:54:47 +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: <6jx5ldpidy2ycrqognfiv5ttqr5ia4dtbryta3kc2mkndrvvgo@qzuakucz765k> <6634386b-afc1-4e31-a2f4-9c1afed2d1d8@huawei.com> <5af62fa9-e71b-412f-8640-502f03fcaa52@huawei.com> <4hicem4rbz5l7wnzaaz3krrl3euh2dmvlah2rb7errrdq5fann@44dvdxirkuzh> <6506e448-3851-436f-9354-42f9ef844d27@huawei.com> From: Yongbang Shi In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemd500013.china.huawei.com (7.221.188.12) > 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? 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!