From patchwork Mon Dec 12 21:00:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 87768 Delivered-To: patches@linaro.org Received: by 10.140.20.101 with SMTP id 92csp1858647qgi; Mon, 12 Dec 2016 13:00:46 -0800 (PST) X-Received: by 10.84.213.130 with SMTP id g2mr188024646pli.43.1481576446809; Mon, 12 Dec 2016 13:00:46 -0800 (PST) Return-Path: Received: from mail-pg0-x231.google.com (mail-pg0-x231.google.com. [2607:f8b0:400e:c05::231]) by mx.google.com with ESMTPS id z70si44996324pff.228.2016.12.12.13.00.46 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Dec 2016 13:00:46 -0800 (PST) Received-SPF: pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c05::231 as permitted sender) client-ip=2607:f8b0:400e:c05::231; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org; spf=pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c05::231 as permitted sender) smtp.mailfrom=john.stultz@linaro.org; dmarc=pass (p=NONE dis=NONE) header.from=linaro.org Received: by mail-pg0-x231.google.com with SMTP id p66so39082390pga.2 for ; Mon, 12 Dec 2016 13:00:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=pnGcfhMmpWOXvYo10vJgDqvVFYt7wrezhVHUdsCMebA=; b=eeJK1mZ7QNleLlpN0xmsg1k8sNohO/gPLaSWmfJ5s5eZj90TcNOofyiN2g8rux+8lU zevamSOKNDGFXIIoNZjBoTBIMBPsN9thIhI8OvOQFBYSczH9yzZ/SSVmbmRIN0N8CrMN AdsXcYEyn/qydAKGnE0nWBI1JyTQ1W3+gFqKY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=pnGcfhMmpWOXvYo10vJgDqvVFYt7wrezhVHUdsCMebA=; b=Pq5oMpNmFcrJwePExhFEYR2QqaE5e0poI0wVYUJPBK09fu6yrfUiItN23ODF8U+i0s eH84vQ+5YkRBFPtJTw5bTx+OVE83pvUJjn3QWC5ZPEcWBLyUOOAhxEcEWrUrGeKyASbJ 4aMZaEGf5TS1an2G2g/3tOjDO/VmNsQbS5nprng+Mmjz7xJEjy0gZZhqu9pfdlGaM74c F3Lgwb+UNOXWSzis/IYrjYv/xe7faitU8EnfmWGvQw+KUWX7D2ao2LjSJPFL0yeQIRi1 iOeZy6I92BeHdCzJGffMRJ6l5ay2Sp2Hm6CrKb5jHaOxpkqtw4DUxLzEt0y6Ra6Uiyf0 NIKw== X-Gm-Message-State: AKaTC01pbqPE5ChSiwh7t0X71u8q29wHfMv64nyaSeAUIzbSMmMorIjNSnZkgUjq89A/4UIrp5s= X-Received: by 10.99.251.69 with SMTP id w5mr33468670pgj.124.1481576446476; Mon, 12 Dec 2016 13:00:46 -0800 (PST) Return-Path: Received: from localhost.localdomain ([2601:1c2:1002:83f0:4e72:b9ff:fe99:466a]) by smtp.gmail.com with ESMTPSA id f3sm41074078pga.45.2016.12.12.13.00.45 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 12 Dec 2016 13:00:45 -0800 (PST) From: John Stultz To: lkml Cc: John Stultz , David Airlie , Archit Taneja , Wolfram Sang , Lars-Peter Clausen , Laurent Pinchart , dri-devel@lists.freedesktop.org Subject: [RFC][PATCH 1/5 v3] drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context Date: Mon, 12 Dec 2016 13:00:37 -0800 Message-Id: <1481576441-23529-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1481576441-23529-1-git-send-email-john.stultz@linaro.org> References: <1481576441-23529-1-git-send-email-john.stultz@linaro.org> I was recently seeing issues with EDID probing, where the logic to wait for the EDID read bit to be set by the IRQ wasn't happening and the code would time out and fail. Digging deeper, I found this was due to the fact that IRQs were disabled as we were running in IRQ context from the HPD signal. Thus this patch changes the logic to handle the HPD signal via a work_struct so we can be out of irq context. With this patch, the EDID probing on hotplug does not time out. Cc: David Airlie Cc: Archit Taneja Cc: Wolfram Sang Cc: Lars-Peter Clausen Cc: Laurent Pinchart Cc: dri-devel@lists.freedesktop.org Reviewed-by: Laurent Pinchart Signed-off-by: John Stultz --- v3: Rename irq_work to hpd_work and remove extra whitespace, as suggested by Laurent --- drivers/gpu/drm/bridge/adv7511/adv7511.h | 2 ++ drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 11 ++++++++++- 2 files changed, 12 insertions(+), 1 deletion(-) -- 2.7.4 diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h b/drivers/gpu/drm/bridge/adv7511/adv7511.h index 992d76c..0396791 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511.h +++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h @@ -317,6 +317,8 @@ struct adv7511 { bool edid_read; wait_queue_head_t wq; + struct work_struct hpd_work; + struct drm_bridge bridge; struct drm_connector connector; diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 8dba729..4fcea44 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -402,6 +402,13 @@ static bool adv7511_hpd(struct adv7511 *adv7511) return false; } +static void adv7511_hpd_work(struct work_struct *work) +{ + struct adv7511 *adv7511 = container_of(work, struct adv7511, hpd_work); + + drm_helper_hpd_irq_event(adv7511->connector.dev); +} + static int adv7511_irq_process(struct adv7511 *adv7511, bool process_hpd) { unsigned int irq0, irq1; @@ -419,7 +426,7 @@ static int adv7511_irq_process(struct adv7511 *adv7511, bool process_hpd) regmap_write(adv7511->regmap, ADV7511_REG_INT(1), irq1); if (process_hpd && irq0 & ADV7511_INT0_HPD && adv7511->bridge.encoder) - drm_helper_hpd_irq_event(adv7511->connector.dev); + schedule_work(&adv7511->hpd_work); if (irq0 & ADV7511_INT0_EDID_READY || irq1 & ADV7511_INT1_DDC_ERROR) { adv7511->edid_read = true; @@ -1006,6 +1013,8 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id) goto err_i2c_unregister_edid; } + INIT_WORK(&adv7511->hpd_work, adv7511_hpd_work); + if (i2c->irq) { init_waitqueue_head(&adv7511->wq);