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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2EE0DC44501 for ; Wed, 15 Jul 2026 19:31:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=hL1GS79qzyM0ipi8jemKvD9nfesfcOl399h19NOhaM8=; b=nqljKynx86+3/0gqEj/tdpnHfF gIaJFRAGCZUXgv9gjfNWjs1QiEVTaX+kTti9nLIlOuwWYKZXlazNlsaNpjbUVSoBLCCwPVripf2Tb xw31FCLMF9rUq1MlN6RSbt9JvnjZdRYLyd+1zUyAZhHZyJ+HM23ZOmU+rLrbnfqCQHMEgTEBOxBHi lLiKlj4KAj07MCfjue4MogceRjljQBBH/XXSzSy/swugf2TPeGqAcqdO5J+B9zb95kPCAGAJGQ9Ia ZbVkgmpFaFCH+RlOWZeVG1Zna0oNWRWZoSoLycS9InyFAt/pl98PMJ3gWC58OzxmQpZPlq+qHQGjg gdymQ0wA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wk5Jp-0000000FmxT-37Xf; Wed, 15 Jul 2026 19:30:57 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wk5Jn-0000000Fmwp-0rSp; Wed, 15 Jul 2026 19:30:56 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Type:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To; bh=hL1GS79qzyM0ipi8jemKvD9nfesfcOl399h19NOhaM8=; b=zb9QXW1XMG4YfPtNV3RG+62Zmd v8UvwL/ktHs4FtJ/TP0zlhZleTu7M3ckwlhFjD4fw+uytYiKG7LFVdi6L8rfGJpoUn9NXkCz66pN8 /qJeCo+4hjVSn+09UJwGZkBRxCikUAhVFdv/Y9jHZhsRA7jr9+/oTwWrn4fM7+AzWXr5cTmo4EQlr fPpdq9Hyo1NSmaiNWEznadQPhH77OjmmymXNzamcUS3zD+zTNqb3owWxhn+mkg5Tv/Pndg4MN0jc+ XA/8uJNplYQGHCcxu061mq29I4T0soEHVGDgIqoMeWlNxc6tMpWJkAUf+VeOvTW/IHgHRScOlzpOk uLO0XDIg==; From: Heiko Stuebner To: Andy Yan , Sebastian Reichel Cc: Sandy Huang , Andy Yan , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Rob Herring , Krzysztof Kozlowski , Conor Dooley , David Airlie , Simona Vetter , Dmitry Baryshkov , Luca Ceresoli , Cristian Ciocaltea , Damon Ding , Dmitry Baryshkov , Alexey Charkov , dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, kernel@collabora.com, linux-arm-kernel@lists.infradead.org, yubing.zhang@rock-chips.com Subject: Re: [PATCH v3 08/10] drm/rockchip: dw_dp: Add runtime PM support Date: Wed, 15 Jul 2026 21:30:27 +0200 Message-ID: <2301403.NgBsaNRSFp@phil> In-Reply-To: References: <20260612-synopsys-dw-dp-improvements-v3-0-dc61e6352508@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260715_123055_248588_702D9D37 X-CRM114-Status: GOOD ( 21.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Am Mittwoch, 15. Juli 2026, 21:00:12 Mitteleurop=C3=A4ische Sommerzeit schr= ieb Sebastian Reichel: > Hello Andy, >=20 > On Tue, Jul 14, 2026 at 06:08:06PM +0800, Andy Yan wrote: > > > @@ -58,6 +59,8 @@ static void dw_dp_rockchip_hpd_sw_sel(void *data, b= ool > > > force_hpd_from_sw) > > > > > > dp->hpd_sel =3D force_hpd_from_sw; > > > > > > + ACQUIRE(pm_runtime_active_auto, pm)(dp->dev); > >=20 > > This can triger HPD irq for USB-C DP AltMode, but for a standard > > DP port, this is no way to acquire runtime, so there will no irq > > when plug in. >=20 > Right. I don't have any RK3588 or RK3576 system exposing a DP > connector directly. This this is non-trivial to test for me :/ >=20 > I see the following options: >=20 > 1. Only enable runtime PM when running in USB-C mode > 2. Mux the HPD pin as GPIO to support waking up with the controller > being suspended; either remux when the controller is awake or use > the same mechanism as USB-C to do software based HPD on top of the > GPIO (which would allow using any GPIO as HPD). > 3. Have a poll function, which wakes up the controller regularly to > check the status >=20 > I consider going for option 1 for now, which allows option 2 to be > implemented as a follow up. Mostly to avoid that the series becomes > as big and messy as the USBDP PHY series became. I'd agree with that solution. I think we can all agree that option 3 is baaaad :-) . So with 1, functionality keeps working, and then someone can put the special HPD handling on top later - the Rock-5-ITX does expose the DP1 (on a hdmi port) Heiko