From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-m3284.qiye.163.com (mail-m3284.qiye.163.com [220.197.32.84]) (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 B29153203AA; Tue, 23 Sep 2025 09:07:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.32.84 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758618458; cv=none; b=GzDg1XIpPS1Aue87rmMDtYYvnMO3PpDMpw0aOZVwj4xaqwz24Sji9KUMWNJKZVUOf6nozNk/qVOJn+TIaF1E66cLnadNH2CZuTgQuIjHEZL9mlwVoEDVVVMsTdfIxMLWxIRjEPTiYtnZNckOIcMVxkHeh/T9M7dicLdRPxSiMuA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758618458; c=relaxed/simple; bh=WuyMBJ83iUtyh9YAIQ2Vbkzc9Fith9baN4biM5bS97g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Awnaw7yfiIGcPLShT1KKxTwfB+2Vi6LRt52jT/o04rOTrwqOMWDLSHh7k8+ZvXTLUjGXtHdkua++HqGVaij4mjB0sxFecS+J2RtlIPMTLdyM2laVfS1WFnQUeDav2dM4zRrLtmWckgHhxiYyRkEUqM48CkHhxuWa4QWpiusPrHw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rock-chips.com; spf=pass smtp.mailfrom=rock-chips.com; dkim=pass (1024-bit key) header.d=rock-chips.com header.i=@rock-chips.com header.b=UnY0x8ew; arc=none smtp.client-ip=220.197.32.84 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rock-chips.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rock-chips.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=rock-chips.com header.i=@rock-chips.com header.b="UnY0x8ew" Received: from [172.16.12.153] (unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 23c505336; Tue, 23 Sep 2025 17:07:26 +0800 (GMT+08:00) Message-ID: <18f55fe7-7c68-4982-916d-11752325c667@rock-chips.com> Date: Tue, 23 Sep 2025 17:07:25 +0800 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 1/7] usb: typec: Add default HPD device when register DisplayPort altmode To: Dmitry Baryshkov Cc: Chaoyi Chen , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Vinod Koul , Kishon Vijay Abraham I , Heiko Stuebner , Sandy Huang , Andy Yan , Yubing Zhang , Frank Wang , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Amit Sunil Dhamne , Heikki Krogerus , Greg Kroah-Hartman , Dragan Simic , Johan Jonker , Diederik de Haas , Peter Robinson , linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, dri-devel@lists.freedesktop.org References: <20250922012039.323-1-kernel@airkyi.com> <20250922012039.323-2-kernel@airkyi.com> Content-Language: en-US From: Chaoyi Chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-HM-Tid: 0a9975d3e93303abkunm8ca4981716a2df X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1ktWUFJV1kPCRoVCBIfWUFZQ0gaQlYeHU1LGkoaSUIeTh1WFRQJFh oXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0tIVUpLSEpPSE xVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=UnY0x8ewyFrxCkRivPth9p+Zl0CdPssh9KDioUgHEl094n0HZ+9pTSLZFY59zOaJdprHdBf7fU2I29XmF7SyPPKTw+K0GYeC8PyJ2j51y0bvpzUZl+70r0Q37Np7Qa+3PWdrnujNiON1rcCOg62YDFABAiIG2g7QPODrOmCn6Lc=; s=default; c=relaxed/relaxed; d=rock-chips.com; v=1; bh=HuXLsMMpc578ltmXayFqyQKez4+ZRrpty5hbaJUkQks=; h=date:mime-version:subject:message-id:from; On 9/23/2025 11:11 AM, Dmitry Baryshkov wrote: > On Tue, Sep 23, 2025 at 09:34:39AM +0800, Chaoyi Chen wrote: >> On 9/23/2025 9:10 AM, Dmitry Baryshkov wrote: >> >>> On Mon, Sep 22, 2025 at 09:20:33AM +0800, Chaoyi Chen wrote: >>>> From: Chaoyi Chen >>>> >>>> Add default DRM AUX HPD bridge device when register DisplayPort >>>> altmode. That makes it redundant for each Type-C driver to implement >>>> a similar registration process in embedded scenarios. >>>> >>>> Signed-off-by: Chaoyi Chen >>>> --- >>>> drivers/usb/typec/altmodes/displayport.c | 27 ++++++++++++++++++++++++ >>>> drivers/usb/typec/altmodes/displayport.h | 2 ++ >>>> drivers/usb/typec/class.c | 8 +++++++ >>>> include/linux/usb/typec_altmode.h | 2 ++ >>>> 4 files changed, 39 insertions(+) >>>> >>>> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c >>>> index 1dcb77faf85d..e026dc6e5430 100644 >>>> --- a/drivers/usb/typec/altmodes/displayport.c >>>> +++ b/drivers/usb/typec/altmodes/displayport.c >>>> @@ -14,6 +14,7 @@ >>>> #include >>>> #include >>>> #include >>>> +#include >>>> #include >>>> #include "displayport.h" >>>> @@ -182,6 +183,10 @@ static int dp_altmode_status_update(struct dp_altmode *dp) >>>> dp->pending_irq_hpd = true; >>>> } >>>> } else { >>>> + if (dp->port->hpd_dev) >>>> + drm_aux_hpd_bridge_notify(dp->port->hpd_dev, >>>> + hpd ? connector_status_connected : >>>> + connector_status_disconnected); >>> There should be no need for these calls. Once the HPD bridge is added to >>> a correct fwnode, the drm_connector_oob_hotplug_event() calls should >>> deliver the signal as expected. >> It seems that only drm_bridge_connector can do this. I'm not sure if I remember correctly. I'll give it a try. > Other connectors can implement the .oob_hotplug_event call. Calling > drm_bridge_hpd_notify() also depends on the connector setting the > callbacks via drm_bridge_hpd_enable(), a step which is done by only a > few drivers. Hmm, let's go over this again. First, drm_connector_oob_hotplug_event() requires a connector fwnode. On the Qualcomm platforms, the fwnode corresponds to the USB-C controller device node, so drm_connector_oob_hotplug_event(dp->connector_fwnode, ..) can handle them directly. But our platform doesn't use the USB-C controller device node as drm connector fwnode :( So I use drm_dp_hpd_bridge_register() and drm_aux_hpd_bridge_notify() here, I think it just create a simple hpd bridge to bridge_list. But drm_connector_oob_hotplug_event() use connector_list instead of bridge_list. > >> >>>> drm_connector_oob_hotplug_event(dp->connector_fwnode, >>>> hpd ? connector_status_connected : >>>> connector_status_disconnected); >>>> @@ -206,6 +211,9 @@ static int dp_altmode_configured(struct dp_altmode *dp) >>>> * configuration is complete to signal HPD. >>>> */ >>>> if (dp->pending_hpd) { >>>> + if (dp->port->hpd_dev) >>>> + drm_aux_hpd_bridge_notify(dp->port->hpd_dev, >>>> + connector_status_connected); >>>> drm_connector_oob_hotplug_event(dp->connector_fwnode, >>>> connector_status_connected); >>>> sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd"); >>>> @@ -391,6 +399,9 @@ static int dp_altmode_vdm(struct typec_altmode *alt, >>>> dp->data.status = 0; >>>> dp->data.conf = 0; >>>> if (dp->hpd) { >>>> + if (dp->port->hpd_dev) >>>> + drm_aux_hpd_bridge_notify(dp->port->hpd_dev, >>>> + connector_status_disconnected); >>>> drm_connector_oob_hotplug_event(dp->connector_fwnode, >>>> connector_status_disconnected); >>>> dp->hpd = false; >>>> @@ -751,6 +762,18 @@ static const struct attribute_group *displayport_groups[] = { >>>> NULL, >>>> }; >>>> +void dp_altmode_hpd_device_register(struct typec_altmode *alt) >>>> +{ >>>> + if (alt->svid != USB_TYPEC_DP_SID) >>>> + return; >>>> + >>>> + alt->hpd_dev = drm_dp_hpd_bridge_register(alt->dev.parent->parent, >>>> + dev_of_node(alt->dev.parent->parent)); >>> This needs at least a comment, what is dev.parent->parent. Also, the >>> of_node is not correct here. It should be a node of the connector, >>> rather than the device itself. Consider USB-C controllers which handle >>> several USB-C connectors (e.g. UCSI). The DRM core won't be able to >>> identify the correct bridge. >> I think  alt.dev->parent->parent is the connector device. Am I missing something? > As I wrote, it needs a comment (in the source file). No, it's not a > connector device, it's a USB-C controller device. There is no guarantee > that there is a separate struct device for the USB-C connector. On > Qualcomm platforms, the device will point to the USB-C controller (TCPM > or UCSI), which contain usb-c-connector(s) as child node(s) in DT. Thanks for the clarification. > >> >> >>>> + if (IS_ERR(alt->hpd_dev)) >>>> + alt->hpd_dev = NULL; >>>> +} >>>> +EXPORT_SYMBOL_GPL(dp_altmode_hpd_device_register); >>> Having the function here will bring a typec -> displayport dependency >>> between drivers (which you didn't document). It means it won't be >>> possible to build typec core into the kernel, having the DP AltMode >>> driver in the module (which also doesn't sound like a good idea). >> It make sense. Perhaps moving it into class.c would be a good idea. >> >> >>>> + >>>> int dp_altmode_probe(struct typec_altmode *alt) >>>> { >>>> const struct typec_altmode *port = typec_altmode_get_partner(alt); >> -- >> Best, >> Chaoyi >> >> >> -- >> linux-phy mailing list >> linux-phy@lists.infradead.org >> https://lists.infradead.org/mailman/listinfo/linux-phy -- Best, Chaoyi