From patchwork Thu Apr 30 11:54:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Whitchurch X-Patchwork-Id: 11522219 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 78BE792A for ; Fri, 1 May 2020 07:24:13 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5793C21974 for ; Fri, 1 May 2020 07:24:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=axis.com header.i=@axis.com header.b="RkbxWm7B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5793C21974 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=axis.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A8CAC6EC1C; Fri, 1 May 2020 07:23:45 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from smtp2.axis.com (smtp2.axis.com [195.60.68.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id ACD066EA6E for ; Thu, 30 Apr 2020 11:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; l=5174; q=dns/txt; s=axis-central1; t=1588247705; x=1619783705; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=ELbkQPF89PGOFSm7MQv+09MJ02P9Ecfguw5yKeXquXE=; b=RkbxWm7BG57SIDA7/9OECrj1JMGVbpNu9hZ8RPV3CxHwQWkMiOmYBl67 30Nv6YfR45HnOSklF/kYLG9RZNq3PYFOE7t+SV1KISeFV6VvxszYosTnP qCKfqoHTfRpxUQXpHQMoM1qG5gp3JkBODy/hEvudDLLKVLVi4lWDvE09y 8RHZ16JIWmQElUpNsBGwt0kcZVbMGzi/+thyUdXUQ9Sekh/2o0Djqg1f3 8wDT0dVfRSsHFIhesysSwvnhs+xZaSeaZcGrcn+97zZ1cJbpUadhnnbCX kdJcn3Pc2gO/kAK44Fii8bNoWTO0acocX/os+WfztpbezpFgs41vjNWP5 g==; IronPort-SDR: 7nF2b83pK1oQbW5qsT7CCdAO1uF//MKs2Mv76gV1dVtM8wXLJccZBSD3T7HM4gaMdkpiCdnRyD 1bfhZeSKisYllSWpIg39CeuBQE/c32sIZgmG9YTK4RT2x4woHcF1BEeILMROsua0sxLqaQC4U7 hq+Kzz0B5tk4Fh9mRcB0ZHiAjeC4mtDqGZ4Cy1vlSCFhy9o1OHMNMG3TOfcn843xK5Lyxg8g3L FskrrcNfAaD9F5xZLN0GpCQnT5C80SNZ22ZQei8Dhb73yJLZBCvqBgpH72tRquLPmsvy3mp0AI OIs= X-IronPort-AV: E=Sophos;i="5.73,334,1583190000"; d="scan'208";a="8031549" From: Vincent Whitchurch To: , Subject: [PATCH v2] drm/bridge: adv7511: Fix cec clock EPROBE_DEFER handling Date: Thu, 30 Apr 2020 13:54:39 +0200 Message-ID: <20200430115439.9649-1-vincent.whitchurch@axis.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Mailman-Approved-At: Fri, 01 May 2020 07:22:25 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jernej.skrabec@siol.net, jonas@kwiboo.se, Vincent Whitchurch , dri-devel@lists.freedesktop.org, hverkuil@xs4all.nl, kernel@axis.com, Laurent.pinchart@ideasonboard.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" If adv7511's devm_clk_get() for the cec clock returns -EPROBE_DEFER, we end up in an infinite probe loop. This happens: (1) adv7511's probe is called. (2) adv7511's probe adds some secondary i2c devices which bind to the dummy driver and thus call driver_deferred_probe_trigger() and increment deferred_trigger_count (see driver_bound()). (3) adv7511's probe returns -EPROBE_DEFER, and since the deferred_trigger_count has changed during the probe call, driver_deferred_probe_trigger() is called immediately (see really_probe()) and adv7511's probe is scheduled. (4) Goto step 1. [ 61.972915] really_probe: bus: 'i2c': really_probe: probing driver adv7511 with device 0-0039 [ 61.992734] really_probe: bus: 'i2c': really_probe: probing driver dummy with device 0-003f [ 61.993343] driver_bound: driver: 'dummy': driver_bound: bound to device '0-003f' [ 61.993626] really_probe: bus: 'i2c': really_probe: bound device 0-003f to driver dummy [ 61.995604] really_probe: bus: 'i2c': really_probe: probing driver dummy with device 0-0038 [ 61.996381] driver_bound: driver: 'dummy': driver_bound: bound to device '0-0038' [ 61.996663] really_probe: bus: 'i2c': really_probe: bound device 0-0038 to driver dummy [ 61.998651] really_probe: bus: 'i2c': really_probe: probing driver dummy with device 0-003c [ 61.999222] driver_bound: driver: 'dummy': driver_bound: bound to device '0-003c' [ 61.999496] really_probe: bus: 'i2c': really_probe: bound device 0-003c to driver dummy [ 62.010050] really_probe: i2c 0-0039: Driver adv7511 requests probe deferral [ 62.011380] really_probe: bus: 'platform': really_probe: probing driver pwm-clock with device clock-cec [ 62.012812] really_probe: platform clock-cec: Driver pwm-clock requests probe deferral [ 62.024679] really_probe: bus: 'i2c': really_probe: probing driver adv7511 with device 0-0039 Fix this by calling devm_clk_get() before registering the secondary devices. Signed-off-by: Vincent Whitchurch --- v2: Add devm_clk_put() in error path. drivers/gpu/drm/bridge/adv7511/adv7511_cec.c | 31 ++++++++------------ drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 11 +++++-- 2 files changed, 21 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c b/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c index a20a45c0b353..f5e9d0b238d2 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c @@ -286,28 +286,17 @@ static const struct cec_adap_ops adv7511_cec_adap_ops = { .adap_transmit = adv7511_cec_adap_transmit, }; -static int adv7511_cec_parse_dt(struct device *dev, struct adv7511 *adv7511) -{ - adv7511->cec_clk = devm_clk_get(dev, "cec"); - if (IS_ERR(adv7511->cec_clk)) { - int ret = PTR_ERR(adv7511->cec_clk); - - adv7511->cec_clk = NULL; - return ret; - } - clk_prepare_enable(adv7511->cec_clk); - adv7511->cec_clk_freq = clk_get_rate(adv7511->cec_clk); - return 0; -} - int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511) { unsigned int offset = adv7511->type == ADV7533 ? ADV7533_REG_CEC_OFFSET : 0; - int ret = adv7511_cec_parse_dt(dev, adv7511); + int ret; - if (ret) - goto err_cec_parse_dt; + if (!adv7511->cec_clk) + goto err_cec_no_clock; + + clk_prepare_enable(adv7511->cec_clk); + adv7511->cec_clk_freq = clk_get_rate(adv7511->cec_clk); adv7511->cec_adap = cec_allocate_adapter(&adv7511_cec_adap_ops, adv7511, dev_name(dev), CEC_CAP_DEFAULTS, ADV7511_MAX_ADDRS); @@ -342,8 +331,12 @@ int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511) err_cec_alloc: dev_info(dev, "Initializing CEC failed with error %d, disabling CEC\n", ret); -err_cec_parse_dt: + clk_disable_unprepare(adv7511->cec_clk); + devm_clk_put(dev, adv7511->cec_clk); + /* Ensure that adv7511_remove() doesn't attempt to disable it again. */ + adv7511->cec_clk = NULL; +err_cec_no_clock: regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, ADV7511_CEC_CTRL_POWER_DOWN); - return ret == -EPROBE_DEFER ? ret : 0; + return 0; } diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 9e13e466e72c..ebc548e23ece 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1122,6 +1122,15 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id) if (ret) return ret; + adv7511->cec_clk = devm_clk_get(dev, "cec"); + if (IS_ERR(adv7511->cec_clk)) { + ret = PTR_ERR(adv7511->cec_clk); + if (ret == -EPROBE_DEFER) + return ret; + + adv7511->cec_clk = NULL; + } + ret = adv7511_init_regulators(adv7511); if (ret) { dev_err(dev, "failed to init regulators\n"); @@ -1226,8 +1235,6 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id) err_unregister_cec: i2c_unregister_device(adv7511->i2c_cec); - if (adv7511->cec_clk) - clk_disable_unprepare(adv7511->cec_clk); err_i2c_unregister_packet: i2c_unregister_device(adv7511->i2c_packet); err_i2c_unregister_edid: