From patchwork Tue Jan 17 00:52:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 91591 Delivered-To: patches@linaro.org Received: by 10.140.20.99 with SMTP id 90csp267292qgi; Mon, 16 Jan 2017 16:52:58 -0800 (PST) X-Received: by 10.99.144.68 with SMTP id a65mr18582801pge.54.1484614378123; Mon, 16 Jan 2017 16:52:58 -0800 (PST) Return-Path: Received: from mail-pg0-x234.google.com (mail-pg0-x234.google.com. [2607:f8b0:400e:c05::234]) by mx.google.com with ESMTPS id k68si23116657pfb.181.2017.01.16.16.52.57 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Jan 2017 16:52:58 -0800 (PST) Received-SPF: pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c05::234 as permitted sender) client-ip=2607:f8b0:400e:c05::234; 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::234 as permitted sender) smtp.mailfrom=john.stultz@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: by mail-pg0-x234.google.com with SMTP id 204so19524444pge.0 for ; Mon, 16 Jan 2017 16:52:57 -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=ZJd8Aw4s2jtqsitss4J7qfGRdNZjizSNsOELilR+CEs=; b=eTc7yLKs694f7s8jlZPqV37I4xMDNoHfT27dxA9QqOmasN/OW3Mge2F4nexlv50KLo ckrq81LraVh1CEjO/oqYTB0T0mQUlBXLCGVmERjhKilDCsJSfm9fuu79aLOLtLObNqOb VLVMgbXkx0rzIKCR892n3htggEdfIpPmgddBU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=ZJd8Aw4s2jtqsitss4J7qfGRdNZjizSNsOELilR+CEs=; b=m432CXVGNJJFz2vHEvwM4XPPzi8RFTKmZEFs4Cv3mGVymL2D5OJJ56iJnBooNf4Y0+ a18+RleyYA7KwHUqF71GWXU7d0bv3NY8JSobKq13Wvtjhp5iaTTqeQVUY+fTVulC9BDy BjF19/5Ns5ZlN1jqxVOYFMRZAKlXxdOdBxVxE+0WkX/VH93lxCP1waqKNfwJ0Zk+m2c3 lu9j8jJ90djlBRSE7mX6KHqIz9ieAx9YNphwHOVtthg6RDXVJLpgbq2ti/+FxD7qS32L VLvbAd2gbFFprxRzAQJg7okOnn9uwFZvjQoD6Ic6JZqs0IRW+c6+MsDOmp9CsUaQL6XP c6Iw== X-Gm-Message-State: AIkVDXKCKfmOEwss7zL2W+8oqIzVgJkIftOCXCQc7jnJI6kceotgKZ2qMCz5zqBmj0sYoHKFtb0= X-Received: by 10.99.131.65 with SMTP id h62mr29175064pge.41.1484614377745; Mon, 16 Jan 2017 16:52:57 -0800 (PST) Return-Path: Received: from localhost.localdomain ([2601:1c2:1002:83f0:4e72:b9ff:fe99:466a]) by smtp.gmail.com with ESMTPSA id q19sm50220516pfl.21.2017.01.16.16.52.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 16 Jan 2017 16:52:57 -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: [PATCH 1/6] drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context Date: Mon, 16 Jan 2017 16:52:47 -0800 Message-Id: <1484614372-15342-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1484614372-15342-1-git-send-email-john.stultz@linaro.org> References: <1484614372-15342-1-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 Tested-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);