This is a note to let you know that I've just added the patch titled drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-bridge-adv7511-use-work_struct-to-defer-hotplug-handing-to-out-of-irq-context.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 518cb7057a59b9441336d2e88a396d52b6ab0cce Mon Sep 17 00:00:00 2001 From: John Stultz <john.stultz@xxxxxxxxxx> Date: Mon, 16 Jan 2017 16:52:47 -0800 Subject: drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context From: John Stultz <john.stultz@xxxxxxxxxx> 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 <airlied@xxxxxxxx> Cc: Archit Taneja <architt@xxxxxxxxxxxxxx> Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Cc: Lars-Peter Clausen <lars@xxxxxxxxxx> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Tested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/1484614372-15342-2-git-send-email-john.stultz@xxxxxxxxxx Signed-off-by: Thong Ho <thong.ho.px@xxxxxxxxxxxxxxx> Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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); Patches currently in stable-queue which might be from john.stultz@xxxxxxxxxx are queue-4.4/drm-bridge-adv7511-use-work_struct-to-defer-hotplug-handing-to-out-of-irq-context.patch queue-4.4/drm-bridge-adv7511-re-write-the-i2c-address-before-edid-probing.patch queue-4.4/drm-bridge-adv7511-switch-to-using-drm_kms_helper_hotplug_event.patch