Firefly Open Source Community

Title: HDMI EDID [Print This Page]

Author: jas-rk Time: 1/2/2015 22:17
Title: HDMI EDID
I noticed in the firefly-rk3288.dts that i2c5 is disabled although the schematics shows it is wired for support. Does this mean that its not possible to get EDID for HDMI? The reason for my question is because with my test 3.14 kernel I'm not seeing any valid EDID information returned from the hdmi driver and wanted to know if EDID should be possible for HDMI.

Author: jas-rk Time: 1/3/2015 05:43

Well, I found out the answer myself?by turning on i2c5 it can detect EDID on my kernel.

Another question is VGA mapped to lcd0 and HDMI to lcd1 under Android ?

Author: e97 Time: 1/3/2015 09:57
Nice work! Thanks for posting this.

--- a/kernel/arch/arm/boot/dts/firefly-rk3288.dts
+++ b/kernel/arch/arm/boot/dts/firefly-rk3288.dts
@@ -535,7 +535,7 @@
};
&i2c5 {
- status = "disabled";
+ status = "okay";
};

Copy the code

Author: zhansb Time: 1/5/2015 09:43

yeah, VGA mapped to lcd0 and HDMI to lcd1

find it in http://www.t-firefly.com/download/firef ... .rar 

Author: jas-rk Time: 1/8/2015 14:44

Even with i2c5 disabled in the dtb, hdmi edid is still detected in Android, so I guessing that it is turned on somewhere in the kernel.

What puzzling me at the moment is what needs to be powered in order to get the hdmi interface working. I can see VDD10_LCD and VCC_18 need to be turned on (via?ACT8846). However with just these 2 ?turned on I'm not getting any interrupts generated from the HDMI controller when plugging in a hdmi source/cable (hot plugin) which leaves me to believe the interface is not fully powered. This is using my test kernel. I also noticed on the VGA side:

1. There is a?gpio (gpio0 GPIO_C1) line to power down the ?SDA7123 which I assume doesn't effect the hdmi interface.

2. The Android VGA drivers seems to set a number of outputs on the ACT8846 when probed which I assume aren't required for hdmi.

I would appreciate if the flyfire team could comment.

Author: zhansb Time: 1/9/2015 17:53

RK3288 HDMI is not use irq to check the plug and unplug.

it use?timer to scan , refer to this file:drivers/video/rockchip/hdmi/rk3288/rk3288_hdmi.c

276 static void rk3288_hdmi_irq_work_func(struct work_struct *work)

Author: jas-rk Time: 1/12/2015 16:50

I'd be interested to know why the Android kernel is polling instead of using interrupts?for hpd detection, possibly because of?the interface VGA??

For those of you who may be interested, I've confirmed that the hdmi interface does work using an interrupt handler for hpd, furthermore?EDID detection also works via i2c5. What is important is that?VDD10_LCD and?VCC_18 need to be powered for hdmi to work.

Author: Anonymous Time: 10/7/2016 21:55
Tip: the author has been banned or deleted automatically shield

Author: Learner379 Time: 7/30/2021 13:23
Hi all,

Can you please let me know how to connect with support team? I am also facing one HDMI related issue in Android-9 in below scenario.

- RK3399 device in ON and connected to TV via HDMI.
- If I trun OFF the TV and wait for some time and then turn ON the TV
- In this scenario failed to get edid error error is coming and TV is running in 720p resolution by default.

And also restarting the RK3399 board is fixing this problem.

Can any one of you please help me with this issue. And let me know if any further information required.

Thanks in Advance.

Author: JamesWilliam12 Time: 10/3/2021 01:54
Thank you for sharing this information with us.

https://clickbankproductreviews.org/java-burn-reviews/

Author: keisor71 Time: 12/27/2022 21:58
Last edited by keisor71 In 12/27/2022 21:59 Editor

interesting informatio

Author: alexhopkins Time: 5/22/2023 11:04
I am impressed with your work and skill. Thank you so much stumble guys

Welcome Firefly Open Source Community (https://bbs.t-firefly.com/)