From 518cb7057a59b9441336d2e88a396d52b6ab0cce Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 16 Jan 2017 16:52:47 -0800 Subject: [PATCH] drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context 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 --- drivers/gpu/drm/bridge/adv7511/adv7511.h | 2 ++ drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 11 ++++++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h b/drivers/gpu/drm/bridge/adv7511/adv7511.h index 039147fde7b0..fe18a5d2d84b 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511.h +++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h @@ -318,6 +318,8 @@ 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 70b426925604..ce5c19c829b9 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; @@ -1070,6 +1077,8 @@ 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); -- 2.20.1