From patchwork Mon Jul 31 07:19:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 13333914 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 23F81C001DC for ; Mon, 31 Jul 2023 07:23:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231472AbjGaHXt (ORCPT ); Mon, 31 Jul 2023 03:23:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231447AbjGaHWe (ORCPT ); Mon, 31 Jul 2023 03:22:34 -0400 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8D1C1BD2 for ; Mon, 31 Jul 2023 00:19:33 -0700 (PDT) Received: by mail-lf1-x12b.google.com with SMTP id 2adb3069b0e04-4fe2503e3easo3423144e87.2 for ; Mon, 31 Jul 2023 00:19:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1690787972; x=1691392772; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=HDhfU2FoK8aIJGXr0hUVQrh/P1Qtr8xU+ls50+YP7vQ=; b=pKUFzvIbDXE4qehMCnW185ujZVoxzM64vjsTHYaa8ZifxCwJAiCOV4K51poAf0woPb muInJ8nf1Af/KfLwxvGlbcAUyoJOZ0qV8NBPaysp7o5K37pth4xxejw2Pg0iBvQYW4JE mZzqjyezpf6KybQarU40lVrLbZwaPufKxzExD2aL3F+CsesXxcNMl05REvmtpK25WGrG TpdhGXnGeN2HSZR+t8j5Trb59cIfT8YhhM1LT41WTyvF+1QwUcNWCsxOKLZ2MKbSy4Yg zdsTSFzD5Xp5hRP3u5GdBIPYiUtm+oUlJptM/AqhbnMiqCNFoAZ/G8n4mCJ9Jhgr4qIw CHAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690787972; x=1691392772; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=HDhfU2FoK8aIJGXr0hUVQrh/P1Qtr8xU+ls50+YP7vQ=; b=aPPj2KvyzAf1d66DYej61IfA4/VquIRXX+4z5WkIGmkddOS4n6QHgkIeQKTkwVjhPI K7xZM4YeEGBmxiLTLv4XxuCmPC7+8lG9t+ghZLerizvpMqXyv4Dq3fPfAjbyepHosXBg Q84WkJLF9vGsLycbkn9zAwvFsy++QtpyQhGTAm1D3aknquXQMNh3P/2llgTcUjuKw11B 6HlHfC288WgMYFqohSIuutkEn16L8BjMKR6MDX/LJr1HGAPI4fwUhGyPktY1lgNOOEf9 xpB4l9bso8POAZ8zP8qIJkbvipfkLPox0M4/d3ME0GJ6lfs9cUnntBsm8/ee9znkU5eE 0Fdw== X-Gm-Message-State: ABy/qLY094er3qAf3ZC+oamlR7tbbvowj2Dt6zyloBhQQVmxV+oQOLnF UISH95AJBZinG/sD4g8bDkRdWg== X-Google-Smtp-Source: APBJJlEFmmxgVpsb4VKdX/OmDgm7CzXZk2Cy1ts84q1OxjZfrnZW6wz1kgkFsMhlbMY/DhcQwIQTHA== X-Received: by 2002:a2e:8ed0:0:b0:2b9:4b2e:5420 with SMTP id e16-20020a2e8ed0000000b002b94b2e5420mr5467379ljl.52.1690787971721; Mon, 31 Jul 2023 00:19:31 -0700 (PDT) Received: from umbar.unikie.fi ([192.130.178.91]) by smtp.gmail.com with ESMTPSA id c4-20020a2ea1c4000000b002b71c128ea0sm2413267ljm.117.2023.07.31.00.19.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jul 2023 00:19:31 -0700 (PDT) From: Dmitry Baryshkov To: David Airlie , Daniel Vetter , Andy Gross , Bjorn Andersson , Konrad Dybcio , Vinod Koul , Kishon Vijay Abraham I , Heikki Krogerus , Greg Kroah-Hartman , Neil Armstrong Cc: dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, linux-usb@vger.kernel.org, freedreno@lists.freedesktop.org Subject: [PATCH v2 0/3] drm/display: simplify support for transparent DRM bridges Date: Mon, 31 Jul 2023 10:19:27 +0300 Message-Id: <20230731071930.3928150-1-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Supporting DP/USB-C can result in a chain of several transparent bridges (PHY, redrivers, mux, etc). This results in drivers having similar boilerplate code for such bridges. Next, these drivers are susceptible to -EPROBE_DEFER loops: the next bridge can either be probed from the bridge->attach callback, when it is too late to return -EPROBE_DEFER, or from the probe() callback, when the next bridge might not yet be available, because it depends on the resources provided by the probing device. Last, but not least, this results in the the internal knowledge of DRM subsystem slowly diffusing into other subsystems, like PHY or USB/TYPEC. To solve all these issues, define a separate DRM helper, which creates separate aux device just for the bridge. During probe such aux device doesn't result in the EPROBE_DEFER loops. Instead it allows the device drivers to probe properly, according to the actual resource dependencies. The bridge auxdevs are then probed when the next bridge becomes available, sparing drivers from drm_bridge_attach() returning -EPROBE_DEFER. Proposed merge strategy: immutable branch with the drm commit, which is then merged into PHY and USB subsystems together with the corresponding patch. Changes since v1: - Added EXPORT_SYMBOL_GPL / MODULE_LICENSE / etc. to drm_simple_bridge Dmitry Baryshkov (3): drm/display: add transparent bridge helper phy: qcom: qmp-combo: switch to DRM_SIMPLE_BRIDGE usb: typec: nb7vpq904m: switch to DRM_SIMPLE_BRIDGE drivers/gpu/drm/display/Kconfig | 9 ++ drivers/gpu/drm/display/Makefile | 2 + drivers/gpu/drm/display/drm_simple_bridge.c | 125 ++++++++++++++++++++ drivers/phy/qualcomm/Kconfig | 2 +- drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 44 +------ drivers/usb/typec/mux/Kconfig | 2 +- drivers/usb/typec/mux/nb7vpq904m.c | 44 +------ include/drm/display/drm_simple_bridge.h | 19 +++ 8 files changed, 161 insertions(+), 86 deletions(-) create mode 100644 drivers/gpu/drm/display/drm_simple_bridge.c create mode 100644 include/drm/display/drm_simple_bridge.h