From 96232dd4b789662f42196395222592b6a276823e Mon Sep 17 00:00:00 2001 From: Dom Cobley Date: Wed, 1 Jun 2022 15:43:51 +0100 Subject: [PATCH] drm/vc4_hdmi: Allow hotplug detect to be forced See: https://forum.libreelec.tv/thread/24783-tv-avr-turns-back-on-right-after-turning-them-off While the kernel provides a :D flag for assuming device is connected, it doesn't stop this function from being called and generating a cec_phys_addr_invalidate message when hotplug is deasserted. That message provokes a flurry of CEC messages which for many users results in the TV switching back on again and it's very hard to get it to stay switched off. It seems to only occur with an AVR and TV connected but has been observed across a number of manufacturers. The issue started with https://github.com/raspberrypi/linux/pull/4371 and this provides an optional way of getting back the old behaviour Signed-off-by: Dom Cobley --- drivers/gpu/drm/vc4/vc4_hdmi.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index f4f685b5a71f8b..0d48e6f1c9954c 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -41,6 +41,8 @@ #include #include #include +#include +#include #include #include #include @@ -113,6 +115,10 @@ #define HDMI_14_MAX_TMDS_CLK (340 * 1000 * 1000) +/* bit field to force hotplug detection. bit0 = HDMI0 */ +static int force_hotplug = 0; +module_param(force_hotplug, int, 0644); + static const char * const output_format_str[] = { [VC4_HDMI_OUTPUT_RGB] = "RGB", [VC4_HDMI_OUTPUT_YUV420] = "YUV 4:2:0", @@ -454,7 +460,9 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector, WARN_ON(pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev)); - if (vc4_hdmi->hpd_gpio) { + if (force_hotplug & BIT(vc4_hdmi->encoder.type - VC4_ENCODER_TYPE_HDMI0)) + status = connector_status_connected; + else if (vc4_hdmi->hpd_gpio) { if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio)) status = connector_status_connected; } else {