From patchwork Wed Aug 2 01:18:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 13337496 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 5D21EC41513 for ; Wed, 2 Aug 2023 01:18:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230283AbjHBBSx (ORCPT ); Tue, 1 Aug 2023 21:18:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229557AbjHBBSu (ORCPT ); Tue, 1 Aug 2023 21:18:50 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EEEA3269A for ; Tue, 1 Aug 2023 18:18:48 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id 38308e7fff4ca-2b9a828c920so97724021fa.1 for ; Tue, 01 Aug 2023 18:18:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1690939127; x=1691543927; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=V+gWA/tO3az5qnPtCpr5Q7+4MvP6fpYV/Vi7gO7EqLw=; b=WkuenX1ZTdY/VOYXWxbQJV8Vc00bZbCUdBzSDngguxOoG6ibp25OywDJSSx75jNId8 jEp4UwttDm1pFZfJzhWp2WIC26nRfduG+Xj1bwckcg87vt1Rv5z+dyqKqMtVMWv/fk1r 8eCoraLT1t5H4p7VcZUH7mNNXZi5x3qcTSK7qeTzNSBlEae8I15/yGpZW1cKnJQxdXRt Cf54hC/ZeMUw2oCwHMmhkZapJFk8YDQr0HSpMrvpR9Uua+ODp+fWyy69iFkIXzWmDZE6 bqzMpzt1MyzIfu8TXYeFCny+buMiUmGpa+ZU2Ws+bfzwyo0Yvq+KRWYBlzB4F9nuXUXo /1cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690939127; x=1691543927; 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=V+gWA/tO3az5qnPtCpr5Q7+4MvP6fpYV/Vi7gO7EqLw=; b=QgherFhUX/pJ2a/fsPjTEZdBDfbvHSaYGCvMZlaewQsOClkubC/YKeZV5nb6xpjBpR sT+AX9PKxz7NSP6eFxFyYiIRO+rRiM3Y5mxOpsaISIsCuQNJQ3A4gaxTvtitlu5IRDaI yaXoz268/7WK0lO3al4jGUjL6jUpqm43Cq3Pu3yHB6phXwtc7NNN/quz86mieGSap5U3 iWl4my75S6C2lM4n8VMdbIMFg9x3yHuDThNTsX6BWrYULZJzgOi5EHPcQZvk+FIeZS7M 21y9Th3hKnK3aPK+Cbyj7jdqTObr6h6lSJj8QtY8bUdyxCMcTKt4nwRnViDXabrtr2SS JudA== X-Gm-Message-State: ABy/qLZTjNx7B6Tgr5B8OqIPBm/CJ9PMbK6VtuOitl5qrytFpCxSs+ln /Z5RD2uHFsf3U0vUzFsCqTW7WA== X-Google-Smtp-Source: APBJJlGTXU+qU/iB+Qs91qxaj6dsnClWjqfDO9bvss9c5WHdTTrVKMq8s3kynB6XVZ1Gf6nY1uUfuw== X-Received: by 2002:a19:2d4b:0:b0:4fb:89e3:5ac6 with SMTP id t11-20020a192d4b000000b004fb89e35ac6mr3626211lft.62.1690939126825; Tue, 01 Aug 2023 18:18:46 -0700 (PDT) Received: from umbar.unikie.fi ([192.130.178.91]) by smtp.gmail.com with ESMTPSA id n14-20020a056512388e00b004faeedbb29dsm2775842lft.64.2023.08.01.18.18.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Aug 2023 18:18:46 -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 v3 0/3] drm/display: simplify support for transparent DRM bridges Date: Wed, 2 Aug 2023 04:18:42 +0300 Message-Id: <20230802011845.4176631-1-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 v2: - ifdef'ed bridge->of_node access (LKP) 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 | 127 ++++++++++++++++++++ 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, 163 insertions(+), 86 deletions(-) create mode 100644 drivers/gpu/drm/display/drm_simple_bridge.c create mode 100644 include/drm/display/drm_simple_bridge.h