From nobody Tue Jun 30 13:04:27 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2F08C433EF for ; Mon, 17 Jan 2022 14:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234397AbiAQOR7 (ORCPT ); Mon, 17 Jan 2022 09:17:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232029AbiAQOR6 (ORCPT ); Mon, 17 Jan 2022 09:17:58 -0500 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F622C061574 for ; Mon, 17 Jan 2022 06:17:58 -0800 (PST) Received: by mail-wm1-x32a.google.com with SMTP id q9-20020a7bce89000000b00349e697f2fbso24096173wmj.0 for ; Mon, 17 Jan 2022 06:17:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=DJwsITSMY4QI1R0GyVDZJD0gSOxLKr++NG45dIxuuJs=; b=RIqG2RM1JSZMzH3Ltu70CUWzXiGPKZkk6KaXW/WMH4QnBcWgVffvRVOIPTxBFWHxNk QEK25D9g9Cofj5DtQrc5AhOtb0wXb7XMWB9w+2/BDyS8T87HBQ1q+KL15jwHX2m0rV/W YBdSd0Nc6gA87MRxxsfyisMmQIghcyXDqbXR2l/yUi7Zyf8NCDjnafAupzL2cIdPlcUl Q7jlKIqf49CRzNjKiMNhpe1uZb62jVfeUOgUzyzFJTmLBVfhqqoh764JVknbA/2R7JJy B0PkWyIYRAKppKAlHG+q44USoznorkTcX6G0FB8M4kaC2Wfta5+c4DwoRzVIMXBNsfLK k5OQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=DJwsITSMY4QI1R0GyVDZJD0gSOxLKr++NG45dIxuuJs=; b=K+HgbH97SYhA4EzEsvK/cIjE/kbGgZuwXatKwrPrfPJz1WhmxAZXvzM5QBpITawRQI A3RlYPtkDwcl2XOCZjrWb+z0VsvWw3v9MLntyX/lmE2tHySZeFB+VsgK8DXuS8QFeik0 oVHNynmEUtkRujhwNeZZ05vfo3pL1u8pXMaMpVj4G0mnLbsf5TiAsVcVNbf61iFD8YZj Txe/EW8RybHAvn3CcU73qjpGJrQ+T1K8TBRdhA5ve3QjMPQp52wCd7Y/6EVbtjdYqWsY 4eVx2R4wd+EAU+GXjWIW5SRui7I52M0ziGUnRcr8brZCRowhgoUKCqLujchxV7CV7sYS dqgw== X-Gm-Message-State: AOAM5321B/w0qSaSA0dQJQ+67dh7Ucrt5wIkJvxnDIzHjrH96LRFOm+e uxUJV70S2M4kXVt6bmddXHDkdA== X-Google-Smtp-Source: ABdhPJx2Lp6ss2rXVGBn2sErjrUmZPIzPgpqhB8Kd0/S/liD97bAVpi21dNqow/jsz25iV/zAWV9AQ== X-Received: by 2002:a5d:5849:: with SMTP id i9mr7839177wrf.358.1642429076455; Mon, 17 Jan 2022 06:17:56 -0800 (PST) Received: from localhost.localdomain ([2001:861:44c0:66c0:c004:9fe1:fbda:2d0c]) by smtp.gmail.com with ESMTPSA id f141sm7975972wmf.30.2022.01.17.06.17.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jan 2022 06:17:55 -0800 (PST) From: Neil Armstrong To: robert.foss@linaro.org Cc: Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se, jernej.skrabec@gmail.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kieran.bingham@ideasonboard.com, biju.das.jz@bp.renesas.com, Neil Armstrong , Kieran Bingham Subject: [PATCH] drm/bridge: dw-hdmi: use safe format when first in bridge chain Date: Mon, 17 Jan 2022 15:17:50 +0100 Message-Id: <20220117141750.1182223-1-narmstrong@baylibre.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When the dw-hdmi bridge is in first place of the bridge chain, this means there is now way to select an input format of the dw-hdmi HW component. Since introduction of display-connector, negociation was broken since the dw-hdmi negociation code only worked when the dw-hdmi bridge was in last position of the bridge chain or behind another bridge also supporting input & output format negociation. Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts cal= lbacks") was introduced to make negociation work again by making display-connector act as a pass-through concerning input & output format negociation. But in the case were the dw-hdmi was single in the bridge chain, for example on Renesas SoCs, with the disply-connector bridge the dw-hdmi is no more single, breaking output format. Reported-by: Biju Das Bisected-by: Kieran Bingham Tested-by: Kieran Bingham Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts cal= lbacks"). Signed-off-by: Neil Armstrong --- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/br= idge/synopsys/dw-hdmi.c index 54d8fdad395f..9f2e1cac0ae2 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts= (struct drm_bridge *bridge, if (!output_fmts) return NULL; =20 - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ - if (list_is_singular(&bridge->encoder->bridge_chain)) { + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselv= es */ + if (list_is_singular(&bridge->encoder->bridge_chain) || + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { *num_output_fmts =3D 1; output_fmts[0] =3D MEDIA_BUS_FMT_FIXED; =20 @@ -2673,6 +2674,10 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts= (struct drm_bridge *bridge, if (!input_fmts) return NULL; =20 + /* If dw-hdmi is the first bridge fall-back to safe output format */ + if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) + output_fmt =3D MEDIA_BUS_FMT_FIXED; + switch (output_fmt) { /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ case MEDIA_BUS_FMT_FIXED: --=20 2.25.1