From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0C3822B9A6; Thu, 3 Jul 2025 15:04:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751555067; cv=none; b=mzrrfLWgLeIDoofvd2/DO8YVL2JkA639pGh1vSJmBf1cdMp2suQeRK79Ku1zMIdA6H6O120AFoOxllbIXyn5PqhIzyPawumEIcqdBbatnd5EW72qtHlJBbabjGcZln0DIO6xr5mJP1FrwzBBWuJHWlIAfyv4XCzCx2dIty5kfQU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751555067; c=relaxed/simple; bh=+uu8CrKX2hOaP63MIg6wnGRGAdJOkT0CDLulLfCL82o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F49BlY7IsSDd5sgSM1vw0mFzaGGFVkWBVFVcNihP+gHmyf6cSbTKY6rpphVzOAHENaIFNPJM05chv9yAad7ZJ5qiTvtM2sC5i5Hy65f/rvj4AYn0PrtAgoAe5Mx6WWawHxp8arthBmZtc5w5iSiHFDuQi3J22zvz57YbwLmILY0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cawGWZUY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="cawGWZUY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87459C4CEE3; Thu, 3 Jul 2025 15:04:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1751555066; bh=+uu8CrKX2hOaP63MIg6wnGRGAdJOkT0CDLulLfCL82o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cawGWZUYfooV5c3qIOJEsTDfaYNkNtE41ZeAuBGXltR/Y+bmtIJUYqSowPOqs7qJ6 QaL92EEHErS1U3gUMPWlE6VQROZO3DKkVI5cP8L9xmtvrnq2dQjxQeMj6vw3GhKiz4 W/yGTmCyWO5jZxeScFCWCEWViZtz322KBHCb6b+8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Max Krummenacher , Douglas Anderson , Ernest Van Hoecke , Jayesh Choudhary , Sasha Levin Subject: [PATCH 6.15 167/263] drm/bridge: ti-sn65dsi86: Add HPD for DisplayPort connector type Date: Thu, 3 Jul 2025 16:41:27 +0200 Message-ID: <20250703144011.054177279@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250703144004.276210867@linuxfoundation.org> References: <20250703144004.276210867@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jayesh Choudhary [ Upstream commit 55e8ff842051b1150461d7595d8f1d033c69d66b ] 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 display sink's connector type. 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 Reviewed-by: Douglas Anderson Tested-by: Ernest Van Hoecke Signed-off-by: Jayesh Choudhary Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20250624044835.165708-1-j-choudhary@ti.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 69 +++++++++++++++++++++++---- 1 file changed, 60 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index c1ed1a3d68447..4ea13e5a3a54a 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -330,12 +330,18 @@ static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata) * 200 ms. We'll assume that the panel driver will have the hardcoded * delay in its prepare and always disable HPD. * - * If HPD somehow makes sense on some future panel we'll have to - * change this to be conditional on someone specifying that HPD should - * be used. + * For DisplayPort bridge type, we need HPD. So we use the bridge type + * to conditionally disable HPD. + * NOTE: The bridge type is set in ti_sn_bridge_probe() but enable_comms() + * can be called before. So for DisplayPort, HPD will be enabled once + * bridge type is set. We are using bridge type instead of "no-hpd" + * property because it is not used properly in devicetree description + * and hence is unreliable. */ - regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE, - HPD_DISABLE); + + if (pdata->bridge.type != DRM_MODE_CONNECTOR_DisplayPort) + regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE, + HPD_DISABLE); pdata->comms_enabled = true; @@ -1172,9 +1178,14 @@ 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); + /* + * Runtime reference is grabbed in ti_sn_bridge_hpd_enable() + * as the chip won't report HPD just after being powered on. + * HPD_DEBOUNCED_STATE reflects correct state only after the + * debounce time (~100-400 ms). + */ + 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; @@ -1197,6 +1208,26 @@ 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); + + /* + * Device needs to be powered on before reading the HPD state + * for reliable hpd detection in ti_sn_bridge_detect() due to + * the high debounce time. + */ + + 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_autosuspend(pdata->dev); +} + static const struct drm_bridge_funcs ti_sn_bridge_funcs = { .attach = ti_sn_bridge_attach, .detach = ti_sn_bridge_detach, @@ -1211,6 +1242,8 @@ 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, @@ -1299,8 +1332,26 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev, pdata->bridge.type = pdata->next_bridge->type == DRM_MODE_CONNECTOR_DisplayPort ? 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; + if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort) { + pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT | + DRM_BRIDGE_OP_HPD; + /* + * 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); + }; drm_bridge_add(&pdata->bridge); -- 2.39.5