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 18865C54F54 for ; Fri, 31 Jul 2026 09:56:06 +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-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=zGIHZsEACYaSirFT7cPZzzvNNQj09PGnO9eQHvTAFAo=; b=aGAXG51hOnIGY4naR9TxyvStF8 SwS7bddEFtlbix1wnKSYI5gPkdHgCJy4fbksGK3PqVqRXMnAslYgrUB7/bxuJNNlrUnd+8LCFzaaL UdZ6xoXWDxwuQfY1lSONTQgVNwLD6viG9PLBs7OMklgQp29ObB84jsMEXJ7WEdwFU7kHxKDWXu0c/ PypTyamlcZWXfRKJkUbbrp56LxS1zCc9YUWtjIhxTwKcdKsnnZwHwnSXHU0v227SW3uXiYseCojQI wSFveiMi/6gFoqfIrFGmN6mclA/gx0i3oCl8ZZi62gv9udL39Twhjb05Cs4raRISxrVBmgvvh5XVH uiIJiQDA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wpjyA-0000000CGAq-3D4H; Fri, 31 Jul 2026 09:55:58 +0000 Received: from mail-m60213.netease.com ([210.79.60.213]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wpjy7-0000000CG8f-11p9; Fri, 31 Jul 2026 09:55:57 +0000 Received: from [172.16.12.74] (unknown [61.154.14.86]) by smtp.qiye.163.com (Hmail) with ESMTP id 48503fdf9; Fri, 31 Jul 2026 17:55:42 +0800 (GMT+08:00) Message-ID: <44ff5316-43cc-46be-b947-ea6e1f5da1bb@rock-chips.com> Date: Fri, 31 Jul 2026 17:55:42 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 0/7] Add HPD support for Rockchip Analogix DP To: =?UTF-8?Q?Heiko_St=C3=BCbner?= , Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Andy Yan Cc: Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Dmitry Baryshkov , Marek Szyprowski , Sebastian Reichel , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org References: <20260730032744.381566-1-damon.ding@rock-chips.com> <2014349.VZ3vTMCxA0@diego> <24131962.ssLaC8jLEa@diego> Content-Language: en-US From: Damon Ding In-Reply-To: <24131962.ssLaC8jLEa@diego> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-HM-Tid: 0a9fb799df1903a8kunm9c7fd6a043b8bf X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVkZShlKVh9MSUwfHxoYSUtPTlYVFA kWGhdVEwETFhoSFyQUDg9ZV1kYEgtZQVlNSlVKTk9VSk9VQ01ZV1kWGg8SFR0UWUFZT0tIVUpLSU 9PT0hVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=T2j7X27HYtjAWW4o20v0+5UDqSqE/WwfWaMehWBW70qp721NPeY28++miQ+glaDp3ABci8X2ZdHwHYrLf6apvAgUZUue0S8LUx9H/TlUjXSWpiZyj+ii1l0Tmv/MnZrWtqwAiur/jZ0hry4MmjviIgCZtNaeNdduxrtRbEUAZaQ=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=zGIHZsEACYaSirFT7cPZzzvNNQj09PGnO9eQHvTAFAo=; h=date:mime-version:subject:message-id:from; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260731_025555_864415_A54F83FF X-CRM114-Status: GOOD ( 31.61 ) 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 Hi Heiko, On 7/31/2026 5:23 PM, Heiko Stübner wrote: > Hi Damon, > > Am Freitag, 31. Juli 2026, 05:08:45 Mitteleuropäische Sommerzeit schrieb Damon Ding: >> On 7/31/2026 2:49 AM, Heiko Stübner wrote: >>> Am Donnerstag, 30. Juli 2026, 05:27:37 Mitteleuropäische Sommerzeit schrieb Damon Ding: >>>> This series improves the HPD (Hotplug Detect) interrupt handling in >>>> the Analogix DP driver to enable reliable native HPD pin detection on >>>> Rockchip platforms, and introduces platform-specific HPD detection >>>> schemes with fine-grained interrupt control. >>> >>> [...] >>> >>>> Tested on RK3576 with both native HPD pin and GPIO HPD configurations. >>>> >>>> Native HPD pin mode: >>>> >>>> &edp { >>>> status = "okay"; >>>> pinctrl-names = "default"; >>>> pinctrl-0 = <&edp_txm0_pins>; >>>> }; >>>> >>>> GPIO HPD mode: >>>> >>>> &edp { >>>> status = "okay"; >>>> pinctrl-names = "default"; >>>> pinctrl-0 = <&edp0_hpd>; >>>> hpd-gpios = <&gpio4 RK_PC1 GPIO_ACTIVE_HIGH>; >>>> }; >>>> >>>> &pinctrl { >>>> edp { >>>> edp0_hpd: edp0-hpd { >>>> rockchip,pins = <4 RK_PC1 0 &pcfg_pull_none>; >>>> }; >>>> }; >>>> }; >>> >>> Yay and thanks a lot for working on that. >>> >>> If I roll my display-port carrier board back to the analogix-dp being >>> the endpoint, this works exactly as expected :-) . >>> >>> I can plug in the display at some point after the boot and have it >>> detected and setup correctly. Same with unplugging it while >>> the system is running. The connection status is correctly reported >>> in sysfs. >>> >>> >>> Though there is a caveat. When the eDP is not the last part, this does not >>> work anymore. The detect function always returns "connected" if there is >>> a next bridge available. >>> >>> My board [0] has a physical DP connector on it, so models it as >>> dp-connector, but in that case the Analogix driver always reports being >>> connected. >>> >>> >>> [0] https://lore.kernel.org/linux-rockchip/20251009225050.88192-3-heiko@sntech.de/ >>> ... same effect with hpd-gpios in either the edp node or dp-connector node >>> >>> >> >> My previous tests were carried out on the modified RK3576 IOTEST board >> DTS based on RK3576 EVB1, which includes dp-connector by default. I also >> did extra verification without dp-connector, and HPD detection works >> correctly in both cases. >> >> I've taken a look at the Tiger board DT configuration. The pinctrl >> settings for the eDP HPD GPIO may need adjustment: >> >> &pinctrl { >> edp0 { >> edp0_hpd_l: edp0-hpd-l-pin { >> rockchip,pins = <4 RK_PB5 RK_FUNC_GPIO &pcfg_pull_down>; >> }; >> }; >> }; >> >> It is recommended to configure GPIO4B5 as pull-down or pll-none. Pull-up >> configuration may prevent GPIO interrupts from being triggered properly, >> resulting in a permanent "connected" status. > > At least on that DP-carrier the pin direction is different. > I.e. it is active-low, meaning 0 for plugged in. > > In the schematics I do see a hw pull up too - so pull-none in the pinconfig > would also be possible, but pull-down is definitly wrong on _this_ board. > > So we're talking about the same code, I put the dts up on [0] . > > I'm currently running with a printk diff [1] to showcase the issue. > > So on boot, with the display unplugged I get: > [ 14.757911] ---> drm_bridge_connector_detect: detect > [ 14.757914] ---> analogix_dp_bridge_detect a > [ 14.757918] ---> drm_bridge_connector_detect: detect > [ 14.773779] ---> analogix_dp_bridge_detect a > [ 14.838658] rockchip-dp fdec0000.edp: failed to read dpcd caps: -110 > [ 14.838662] [drm:analogix_dp_bridge_atomic_enable [analogix_dp]] *ERROR* dp commit error, ret = -110 > [ 14.838670] rockchip-dp fdec0000.edp: failed to set bridge, retry: 0 > [ 14.884791] rockchip-dp fdec0000.edp: failed to read dpcd caps: -110 > [ 14.884793] [drm:analogix_dp_bridge_atomic_enable [analogix_dp]] *ERROR* dp commit error, ret = -110 > [ 14.884796] rockchip-dp fdec0000.edp: failed to set bridge, retry: 1 > [ 14.930925] rockchip-dp fdec0000.edp: failed to read dpcd caps: -110 > [ 14.930927] [drm:analogix_dp_bridge_atomic_enable [analogix_dp]] *ERROR* dp commit error, ret = -110 > [ 14.930930] rockchip-dp fdec0000.edp: failed to set bridge, retry: 2 > [ 14.977032] rockchip-dp fdec0000.edp: failed to read dpcd caps: -110 > [ 14.977034] [drm:analogix_dp_bridge_atomic_enable [analogix_dp]] *ERROR* dp commit error, ret = -110 > [ 14.977037] rockchip-dp fdec0000.edp: failed to set bridge, retry: 3 > [ 15.023150] rockchip-dp fdec0000.edp: failed to read dpcd caps: -110 > [ 15.023152] [drm:analogix_dp_bridge_atomic_enable [analogix_dp]] *ERROR* dp commit error, ret = -110 > [ 15.023155] rockchip-dp fdec0000.edp: failed to set bridge, retry: 4 > [ 15.023168] rockchip-dp fdec0000.edp: too many times retry set bridge, give it up > [ 15.052485] Console: switching to colour frame buffer device 80x30 > [ 15.210457] rockchip-drm display-subsystem: [drm] fb0: rockchipdrmfb frame buffer device > [ 15.223444] ---> drm_bridge_connector_detect: detect > [ 15.231974] ---> analogix_dp_bridge_detect a > [ 15.239587] ---> drm_bridge_connector_detect: detect > [ 15.245341] ---> analogix_dp_bridge_detect a > > So analogix_dp_bridge_detect() is called and always returns connected. > > Plugging in the the display, I get: > [ 290.592096] ---> display_connector_detect gpio value is 1 {display-connector returning connected} > [ 290.598648] ---> drm_bridge_connector_detect: detect > [ 290.604637] ---> analogix_dp_bridge_detect a > [ 290.609826] ---> drm_bridge_connector_detect: detect > [ 290.615784] ---> analogix_dp_bridge_detect a > > Unplugging the display, I get: > [ 302.081444] ---> display_connector_detect gpio value is 0 {display-connector returning disconnected} > [ 302.087996] ---> drm_bridge_connector_detect: detect > [ 302.093945] ---> analogix_dp_bridge_detect a > [ 302.099131] ---> drm_bridge_connector_detect: detect > [ 302.105090] ---> analogix_dp_bridge_detect a > [ 302.144834] ---> drm_bridge_connector_detect: detect > [ 302.150784] ---> analogix_dp_bridge_detect a > [ 302.155933] ---> drm_bridge_connector_detect: detect > [ 302.161859] ---> analogix_dp_bridge_detect a > > > So it looks like on the gpio-side the detection is correct and/but > analogix_dp_bridge_detect() is always returning a connected state > ("b" output is never reached). > > I'm still working on understanding how the whole detection logic works > in drm ;-) . > > I think I've spotted the environmental difference between our setups. Your DTS places the hpd-gpios property under the dp-connector node, which is a scenario I haven't covered yet. I will reproduce and test this case locally. As a quick experiment, could you try removing hpd-gpios from dp-connector and move it under the edp node instead? As expected, GPIO HPD should work properly with that configuration. Best regards, Damon > > > [0] https://github.com/mmind/linux-rockchip/blob/dev/v7.3/rk3588-tiger-dp-carrier-v5/arch/arm64/boot/dts/rockchip/rk3588-tiger-displayport-carrier.dts > [1] > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > index 7a89548a7a885..0accdf62637ae 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > @@ -915,8 +915,10 @@ analogix_dp_bridge_detect(struct drm_bridge *bridge, struct drm_connector *conne > struct analogix_dp_device *dp = to_dp(bridge); > enum drm_connector_status status = connector_status_disconnected; > > +printk("---> %s a\n", __func__); > if (dp->plat_data->next_bridge) > return connector_status_connected; > +printk("---> %s b\n", __func__); > > if (!analogix_dp_detect_hpd(dp)) > status = connector_status_connected; > diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c > index 16c0631adeb18..b0c07694b82e3 100644 > --- a/drivers/gpu/drm/bridge/display-connector.c > +++ b/drivers/gpu/drm/bridge/display-connector.c > @@ -45,6 +45,7 @@ static enum drm_connector_status display_connector_detect(struct drm_bridge *bri > struct display_connector *conn = to_display_connector(bridge); > > if (conn->hpd_gpio) { > +printk("---> %s gpio value is %d\n", __func__, gpiod_get_value_cansleep(conn->hpd_gpio)); > if (gpiod_get_value_cansleep(conn->hpd_gpio)) > return connector_status_connected; > else > @@ -84,6 +85,7 @@ static enum drm_connector_status display_connector_detect(struct drm_bridge *bri > static enum drm_connector_status > display_connector_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector) > { > +printk("---> %s\n", __func__); > return display_connector_detect(bridge); > } > > diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c > index 649969fca1413..8816d837c9a77 100644 > --- a/drivers/gpu/drm/display/drm_bridge_connector.c > +++ b/drivers/gpu/drm/display/drm_bridge_connector.c > @@ -218,6 +218,7 @@ drm_bridge_connector_detect(struct drm_connector *connector, bool force) > enum drm_connector_status status; > > if (detect) { > +printk("---> %s: detect\n", __func__); > status = detect->funcs->detect(detect, connector); > > if (hdmi) > > > > >