Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751648AbdILRRg (ORCPT ); Tue, 12 Sep 2017 13:17:36 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48390 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751807AbdILQ5O (ORCPT ); Tue, 12 Sep 2017 12:57:14 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Airlie , Archit Taneja , Wolfram Sang , Lars-Peter Clausen , Laurent Pinchart , dri-devel@lists.freedesktop.org, John Stultz , Thong Ho , Nhan Nguyen Subject: [PATCH 4.4 23/31] drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context Date: Tue, 12 Sep 2017 09:56:18 -0700 Message-Id: <20170912165248.541459149@linuxfoundation.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170912165247.436880944@linuxfoundation.org> References: <20170912165247.436880944@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2868 Lines: 87 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Stultz commit 518cb7057a59b9441336d2e88a396d52b6ab0cce upstream. 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 Signed-off-by: Archit Taneja Link: http://patchwork.freedesktop.org/patch/msgid/1484614372-15342-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thong Ho Signed-off-by: Nhan Nguyen Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i2c/adv7511.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i2c/adv7511.c +++ b/drivers/gpu/drm/i2c/adv7511.c @@ -36,7 +36,10 @@ struct adv7511 { bool edid_read; wait_queue_head_t wq; + struct work_struct hpd_work; + struct drm_encoder *encoder; + struct drm_connector connector; bool embedded_sync; enum adv7511_sync_polarity vsync_polarity; @@ -429,6 +432,13 @@ static bool adv7511_hpd(struct 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; @@ -446,7 +456,7 @@ static int adv7511_irq_process(struct ad regmap_write(adv7511->regmap, ADV7511_REG_INT(1), irq1); if (process_hpd && irq0 & ADV7511_INT0_HDP && adv7511->encoder) - drm_helper_hpd_irq_event(adv7511->encoder->dev); + schedule_work(&adv7511->hpd_work); if (irq0 & ADV7511_INT0_EDID_READY || irq1 & ADV7511_INT1_DDC_ERROR) { adv7511->edid_read = true; @@ -922,6 +932,8 @@ static int adv7511_probe(struct i2c_clie if (!adv7511->i2c_edid) return -ENOMEM; + INIT_WORK(&adv7511->hpd_work, adv7511_hpd_work); + if (i2c->irq) { init_waitqueue_head(&adv7511->wq);