From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fllvem-ot04.ext.ti.com (fllvem-ot04.ext.ti.com [198.47.19.246]) (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 51F0710E5 for ; Thu, 12 Jun 2025 04:40:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.19.246 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749703203; cv=none; b=ncJLj4gQHFH24ELX1j1vUxlxy9L/48xSU1GitV6PP32x/63V9jj+ijMBYpH/Seaj8FDIF9lXOnr78KbD0IPIjJYJRGviAoegsxYK03o6V1HeIVpNxPBUVu6Ss9SlfXBFokOsEU36XUTNNNkgEoDtCUBwxjW+1Q5IYRi/PJuC5Fg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749703203; c=relaxed/simple; bh=TzrB5ln5BEwd6+5oPJTvdv9bORW1mr/Afd6LEpVbqbo=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=jb0+ZgTXtSRVSnElNFa020X3OJnZmNHqzcpHEbJUpv3nlsLl67p18QEfIQ/ZXJ6OOdlkpFGfwmB9CwUcSuTwA0Z6AqCXS1LdKqi86ccyLK8H8pKjm/ltHGZBc4niVJJ4US+VkA+eG12IogiG9a6J/7d8ix/G4/tyr1PJvxIfskQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=j2LX2uXk; arc=none smtp.client-ip=198.47.19.246 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="j2LX2uXk" Received: from lelvem-sh02.itg.ti.com ([10.180.78.226]) by fllvem-ot04.ext.ti.com (8.15.2/8.15.2) with ESMTP id 55C4dWOW1576748; Wed, 11 Jun 2025 23:39:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1749703172; bh=hQmgZzGREthGmoNBCC+PlQ5o5+kf+VtcbzCJpE4Ljxw=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=j2LX2uXkWeHl+IfDUkTlljjlGwPCLubacRzJvVoBb//c8uF0j5R8ZzRdv++eY/3CT CcrDWYBvAfSuy0IKCBXU0RwvU0P1dZWg6Xpql3Gawv575pG4n3jDGFtZPTJbNloNlX Qd4f0agEZLzAZvZgL0vZu0WpSRBwY+tSqKBNBehk= Received: from DFLE110.ent.ti.com (dfle110.ent.ti.com [10.64.6.31]) by lelvem-sh02.itg.ti.com (8.18.1/8.18.1) with ESMTPS id 55C4dWEx3357119 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA256 bits=128 verify=FAIL); Wed, 11 Jun 2025 23:39:32 -0500 Received: from DFLE111.ent.ti.com (10.64.6.32) by DFLE110.ent.ti.com (10.64.6.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.55; Wed, 11 Jun 2025 23:39:31 -0500 Received: from lelvem-mr05.itg.ti.com (10.180.75.9) by DFLE111.ent.ti.com (10.64.6.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.55 via Frontend Transport; Wed, 11 Jun 2025 23:39:31 -0500 Received: from [172.24.227.14] (jayesh-hp-z2-tower-g5-workstation.dhcp.ti.com [172.24.227.14]) by lelvem-mr05.itg.ti.com (8.18.1/8.18.1) with ESMTP id 55C4dPMo1577019; Wed, 11 Jun 2025 23:39:26 -0500 Message-ID: <547a35f4-abc0-4808-9994-ccc70eb3c201@ti.com> Date: Thu, 12 Jun 2025 10:09:24 +0530 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 v4] drm/bridge: ti-sn65dsi86: Add HPD for DisplayPort connector type To: Doug Anderson CC: , , , , , , , , , , , , , , , , , , , References: <20250611052947.5776-1-j-choudhary@ti.com> Content-Language: en-US From: Jayesh Choudhary In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-C2ProcessedOrg: 333ef613-75bf-4e12-a4b1-8e3623f5dcea Hello Doug, On 12/06/25 03:08, Doug Anderson wrote: > Hi, > > On Tue, Jun 10, 2025 at 10:29 PM Jayesh Choudhary wrote: >> >> @@ -1195,9 +1203,17 @@ static enum drm_connector_status ti_sn_bridge_detect(struct drm_bridge *bridge) >> struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge); >> int val = 0; >> >> - pm_runtime_get_sync(pdata->dev); >> + /* >> + * The chip won't report HPD right after being powered on as >> + * HPD_DEBOUNCED_STATE reflects correct state only after the >> + * debounce time (~100-400 ms). >> + * So having pm_runtime_get_sync() and immediately reading >> + * the register in detect() won't work, and adding delay() >> + * in detect will have performace impact in display. >> + * So remove runtime calls here. > > That last sentence makes sense in a commit message, but not long term. > Someone reading the code later won't understand what "remove" means. > If you change "remove" to "omit" then it all makes sense, though. You > could also say that a pm_runtime reference will be grabbed by > ti_sn_bridge_hpd_enable(). Okay. Will edit this. > > >> + */ >> + >> regmap_read(pdata->regmap, SN_HPD_DISABLE_REG, &val); >> - pm_runtime_put_autosuspend(pdata->dev); >> >> return val & HPD_DEBOUNCED_STATE ? connector_status_connected >> : connector_status_disconnected; >> @@ -1220,6 +1236,20 @@ static void ti_sn65dsi86_debugfs_init(struct drm_bridge *bridge, struct dentry * >> debugfs_create_file("status", 0600, debugfs, pdata, &status_fops); >> } >> >> +static void ti_sn_bridge_hpd_enable(struct drm_bridge *bridge) >> +{ >> + struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge); >> + >> + pm_runtime_get_sync(pdata->dev); >> +} >> + >> +static void ti_sn_bridge_hpd_disable(struct drm_bridge *bridge) >> +{ >> + struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge); >> + >> + pm_runtime_put_sync(pdata->dev); >> +} >> + >> static const struct drm_bridge_funcs ti_sn_bridge_funcs = { >> .attach = ti_sn_bridge_attach, >> .detach = ti_sn_bridge_detach, >> @@ -1234,6 +1264,8 @@ static const struct drm_bridge_funcs ti_sn_bridge_funcs = { >> .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, >> .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, >> .debugfs_init = ti_sn65dsi86_debugfs_init, >> + .hpd_enable = ti_sn_bridge_hpd_enable, >> + .hpd_disable = ti_sn_bridge_hpd_disable, >> }; >> >> static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata, >> @@ -1322,7 +1354,8 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev, >> ? DRM_MODE_CONNECTOR_DisplayPort : DRM_MODE_CONNECTOR_eDP; >> >> if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort) >> - pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT; >> + pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT | >> + DRM_BRIDGE_OP_HPD; > > I think you also need this in the "DRM_MODE_CONNECTOR_DisplayPort" if test: > > /* > * If comms were already enabled they would have been enabled > * with the wrong value of HPD_DISABLE. Update it now. Comms > * could be enabled if anyone is holding a pm_runtime reference > * (like if a GPIO is in use). Note that in most cases nobody > * is doing AUX channel xfers before the bridge is added so > * HPD doesn't _really_ matter then. The only exception is in > * the eDP case where the panel wants to read the EDID before > * the bridge is added. We always consistently have HPD disabled > * for eDP. > */ > mutex_lock(&pdata->comms_mutex); > if (pdata->comms_enabled) > regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, > HPD_DISABLE, 0); > mutex_unlock(&pdata->comms_mutex); > > Does that sound right? Here I don't think it is necessary to add this because enable_comms will be called again after probe either in hpd_enable() (in case refclk exist) or pre_enable() (in case it doesn't) with correct value. If this seems okay then I will roll v5 with just the typo fixed in the comments in detect(). Warm Regards, Jayesh