| Message ID | 20140119195844.202f021b@armhf (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Jan 19, 2014 at 07:58:44PM +0100, Jean-Francois Moine wrote: > This patch refines the connection status testing both bits RXSENS and > HPD of the CEC register giving the connection level. Can you explain why this is necessary? I believe this is not necessary for the following reason: HDMI cables are required to mate in a certain order: - First to mate is the shell. - Second are all pins with the exception of the +5V line. - Third is the +5V line. Sinks are not permitted to assert the HPD line until the EDID memory is ready to be read, and +5V is indicated from the source. Hence, HPD will not be asserted until the connector is fully mated, and there are receivers available on the line. This doesn't indicate whether the sink is powered and able to display a picture - it merely means that the sink is present and valid EDID is available to be read. That's all that we really need here.
diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index 013a67c..ea7d1b4 100644 --- a/drivers/gpu/drm/i2c/tda998x_drv.c +++ b/drivers/gpu/drm/i2c/tda998x_drv.c @@ -1050,7 +1050,9 @@ tda998x_encoder_detect(struct drm_encoder *encoder, struct tda998x_priv *priv = to_tda998x_priv(encoder); uint8_t val = cec_read(priv, REG_CEC_RXSHPDLEV); - return (val & CEC_RXSHPDLEV_HPD) ? connector_status_connected : + return (val & (CEC_RXSHPDLEV_RXSENS | CEC_RXSHPDLEV_HPD)) == + (CEC_RXSHPDLEV_RXSENS | CEC_RXSHPDLEV_HPD) ? + connector_status_connected : connector_status_disconnected; }
This patch refines the connection status testing both bits RXSENS and HPD of the CEC register giving the connection level. Signed-off-by: Jean-Francois Moine <moinejf@free.fr> --- drivers/gpu/drm/i2c/tda998x_drv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)