From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lelvem-ot02.ext.ti.com (lelvem-ot02.ext.ti.com [198.47.23.235]) (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 1076D1632C8 for ; Thu, 29 May 2025 11:42:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.23.235 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748518946; cv=none; b=bA2gtuChBiUFnuXHdwA4YPkcm+U7rQySAKpj2Rkp3S5pjut1OooBDbz1qAvCBjSGC7CTnfslWVUzKX4Qobzk5VxwGwZ9vp43XoF5BTPlDX9sgorqU71DZO7I5OY9V0T58/yu96E6K9wHp724m5QMcMysAy0GSuXU7qpotAhJc6o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748518946; c=relaxed/simple; bh=bMfENQufEvemZOu+eUsLQ0d36rEkoQi1H1y1oZxogNQ=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=Bx9bYed/dkhyYbwzbYqLShsMktIDxve+vcuhtervRYzm2GNq5deu9OI1cs0Hd/ij7gaVu7C6N8q3GT+p1ysnP//g7TmgyUxBG8GJy9tLFQ++UlooN84DYowk6ditbPOAKawPNMRCMG/b4+AowdA0t5yoCr0wZWqxorZGrDswLqc= 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=ealYKoL0; arc=none smtp.client-ip=198.47.23.235 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="ealYKoL0" Received: from fllvem-sh03.itg.ti.com ([10.64.41.86]) by lelvem-ot02.ext.ti.com (8.15.2/8.15.2) with ESMTP id 54TBRSIh2386088; Thu, 29 May 2025 06:27:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1748518048; bh=SjrfzujuIx6mXoh/sKloR0Oj+ExZeeZMWNrjShR1Za4=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=ealYKoL09A6dW2maQoteU//EIZx3YnST3LMmcI3D8lptMcCoK/8DvXn3fE68a3jub scwNGoqUyrakRQSBSYaYJE3gH/IXL/y01Ebm1RGtoMLGv2Asdzj9kvw+b9ooE+uQBK nJAfxBaSlSgNcPlqUo865Fsiv0ZinXxpXAQnolZM= Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by fllvem-sh03.itg.ti.com (8.18.1/8.18.1) with ESMTPS id 54TBRRWv062472 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA256 bits=128 verify=FAIL); Thu, 29 May 2025 06:27:27 -0500 Received: from DLEE105.ent.ti.com (157.170.170.35) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Thu, 29 May 2025 06:27:26 -0500 Received: from lelvem-mr05.itg.ti.com (10.180.75.9) by DLEE105.ent.ti.com (157.170.170.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Thu, 29 May 2025 06:27:26 -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 54TBRKl71518842; Thu, 29 May 2025 06:27:21 -0500 Message-ID: <2baf3c31-3edf-4c26-bd44-1d0560134871@ti.com> Date: Thu, 29 May 2025 16:57:20 +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 v3] drm/bridge: ti-sn65dsi86: Add HPD for DisplayPort connector type To: , , , , , , , , CC: , , , , , , , , , , References: <20250529110418.481756-1-j-choudhary@ti.com> Content-Language: en-US From: Jayesh Choudhary In-Reply-To: <20250529110418.481756-1-j-choudhary@ti.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-C2ProcessedOrg: 333ef613-75bf-4e12-a4b1-8e3623f5dcea On 29/05/25 16:34, Jayesh Choudhary wrote: > By default, HPD was disabled on SN65DSI86 bridge. When the driver was > added (commit "a095f15c00e27"), the HPD_DISABLE bit was set in pre-enable > call which was moved to other function calls subsequently. > Later on, commit "c312b0df3b13" added detect utility for DP mode. But with > HPD_DISABLE bit set, all the HPD events are disabled[0] and the debounced > state always return 1 (always connected state). > > Set HPD_DISABLE bit conditionally based on "no-hpd" property. > Since the HPD_STATE is reflected correctly only after waiting for debounce > time (~100-400ms) and adding this delay in detect() is not feasible > owing to the performace impact (glitches and frame drop), remove runtime > calls in detect() and add hpd_enable()/disable() bridge hooks with runtime > calls, to detect hpd properly without any delay. > > [0]: (Pg. 32) > > Fixes: c312b0df3b13 ("drm/bridge: ti-sn65dsi86: Implement bridge connector operations for DP") > Cc: Max Krummenacher > Signed-off-by: Jayesh Choudhary > --- > > Changelog v2->v3: > - Change conditional based on no-hpd property to address [1] > - Remove runtime calls in detect() with appropriate comments > - Add hpd_enable() and hpd_disable() in drm_bridge_funcs > - Not picking up "Tested-by" tag as there are new changes > > v2 patch link: > > > [1]: > > This would also require dts changes in all the nodes of sn65dsi86 > to ensure that they have no-hpd property. DTS patch is posted now: > > drivers/gpu/drm/bridge/ti-sn65dsi86.c | 40 +++++++++++++++++++++++---- > 1 file changed, 35 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > index 60224f476e1d..e9ffc58acf58 100644 > --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > @@ -190,6 +190,7 @@ struct ti_sn65dsi86 { > u8 ln_assign; > u8 ln_polrs; > bool comms_enabled; > + bool no_hpd; > struct mutex comms_mutex; > > #if defined(CONFIG_OF_GPIO) > @@ -352,8 +353,10 @@ static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata, > * change this to be conditional on someone specifying that HPD should > * be used. > */ > - regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE, > - HPD_DISABLE); > + > + if (pdata->no_hpd) > + regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE, > + HPD_DISABLE); > > pdata->comms_enabled = true; > > @@ -1195,9 +1198,17 @@ 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. > + */ > + > 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 +1231,20 @@ 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 +1259,8 @@ 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 +1349,8 @@ 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; > > drm_bridge_add(&pdata->bridge); > > @@ -1935,6 +1963,8 @@ static int ti_sn65dsi86_probe(struct i2c_client *client) > return dev_err_probe(dev, PTR_ERR(pdata->refclk), > "failed to get reference clock\n"); > > + pdata->no_hpd = of_property_read_bool(dev->of_node, "no-hpd"); > + > pm_runtime_enable(dev); > pm_runtime_set_autosuspend_delay(pdata->dev, 500); > pm_runtime_use_autosuspend(pdata->dev);