topic Re: Kernel Hangs... once HDMI enabled in u-boot in i.MX Processors

Kernel Hangs... once HDMI enabled in u-boot

nayanpatel — Thu, 03 Aug 2017 06:28:11 GMT

I have been using SCM imx6 board. updated u-boot to have splash screen and deployed on board. I enabled HDMI detect in board configuration of uboot and uboot is able to detect HDMI display and also showing Splash screen on the UI. After making aforementioned changes my setup hangs at

Starting Kernel.....

To make sure whether it is due to HDMI changes which i did for Splash screen, i have removed HDMI cabel and now kernel is able to boot successfully with out any issue. Just want to know where am i making mistakes? I need to have splash screen in uboot and followed by Qt application on UI.

Re: Kernel Hangs... once HDMI enabled in u-boot

nayanpatel — Thu, 03 Aug 2017 07:06:17 GMT

I have updated display structure in board configuration file as per following to detect HDMI in uboot:

struct display_info_t const displays[] = {{
.bus = -1,
.addr = 0,
.pixfmt = IPU_PIX_FMT_RGB666,
.detect = detect_hdmi, // Earlier it was NULL
.enable = enable_lvds,
.mode = {
.name = "Hannstar-XGA",
.refresh = 60,
.xres = 1024,
.yres = 768,
.pixclock = 15385,
.left_margin = 220,
.right_margin = 40,
.upper_margin = 21,
.lower_margin = 7,
.hsync_len = 60,
.vsync_len = 10,
.sync = FB_SYNC_EXT,
.vmode = FB_VMODE_NONINTERLACED
} },

Now, uboot is able to detect HDMI with correct resolution but kernel hangs when HDMI is detected in uboot (HDMI cable is connected). If i remove HDMI cable and reset then uboot and kernel loads perfectly with out any issue. Need help :smileyhappy:

Re: Kernel Hangs... once HDMI enabled in u-boot

igorpadykov — Thu, 03 Aug 2017 23:42:01 GMT

Hi Nayan

this may be related to

Bug 6703 – Kernel hangs on boot when HDMI cable is plugged

had you tried nxp Demo Image

Board Support Packages (3)
Demo Images - QWKS Board based on SCM-i.MX 6D/Q
http://www.nxp.com/products/single-chip-modules/quick-start-board-for-scm-i.mx-6dq:QWKS-SCM-IMX6DQ?fpsp=1&tab=Design_Tools_Tab

also one can try attached patch developed by other customers

Best regards
igor
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Re: Kernel Hangs... once HDMI enabled in u-boot

nayanpatel — Tue, 08 Aug 2017 12:45:25 GMT

Thank you igorpadykov‌.!

Let's consider my scenario, I need to have HDMI detected in both kernel and uboot. as we are going to show uboot and kernel splash screen on HDMI display. I currently have following things working on board without any issue:

u-boot with disabled HDMI + Kernel is able to detect HDMI and have splash screen ( Configured in kernel ). Over here we have splash screen delayed by 5 to 6 seconds till kernel has init script for Splash screen executed.

To overcome the blank screen after switching on we have decided to have splash screen from u-boot as well. So, we have enabled HDMI detection in u-boot and also enabled splash screen. But after making those changes Kernel is not able to boot-up. so, our final expectation is like below:

U-boot with splash screen loads first and load logo in HDMI display till the kernel init scripts loads splash screen on the HDMI display, Just need some help to have HDMI detected in uboot as well along with splash screen in both uboot and kernel.

can you please suggest any patches, so we can have splash screen working in both uboot and kernel along with HDMI display and no hangs with kernel after bootup?

Re: Kernel Hangs... once HDMI enabled in u-boot

christian_neuwi — Thu, 14 Sep 2017 08:54:03 GMT

Igor,

I have exactly the same problem that Nayan described. The previously attached patch causes the Kernel not to hang anymore, but the HDMI output doesn't work either.

Any other suggestions?

Thanks,

Chris.

Re: Kernel Hangs... once HDMI enabled in u-boot

igorpadykov — Thu, 14 Sep 2017 09:21:02 GMT

Hi Chris

please check

Patch to support uboot logo keep from uboot to kernel for NXP Linux and Android BSP (HDMI, LCD and LVDS)

Best regards
igor

Re: Kernel Hangs... once HDMI enabled in u-boot

fabio_estevam — Thu, 14 Sep 2017 15:57:11 GMT

Please try this patch:

https://github.com/Freescale/linux-fslc/commit/09845b886c1198c9461de424ffd95dde363324c1

Re: Kernel Hangs... once HDMI enabled in u-boot

christian_neuwi — Mon, 18 Sep 2017 18:28:22 GMT

Thanks, Fabio.

This seems to do the trick :-)