gtking pro mainline kernel panic on early init

teacup · July 25, 2020 at 8:51 AM

Any idea what may cause following kernel panic:

Code

[    0.000000] SError Interrupt on CPU0, code 0xbf000000 -- SError
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.3.0 #2
[    0.000000] Hardware name: Hardkernel ODROID-N2 (DT)
[    0.000000] pstate: 40000085 (nZcv daIf -PAN -UAO)
[    0.000000] pc : new_slab+0x594/0xa08
[    0.000000] lr : new_slab+0x584/0xa08

I need to test some older mainline kernels for bisecting an usb3 problem that appears with haupage WinTV-hualHD tuner.

Built mainline libreelec for amlogic from chewitt, the version with 5.7 kernel boots ok with gt-king pro. Downgraded to version with 5.1 kernel and got the above panic, using dtb from 5.7 for gt king pro. Tested version with 5.3 kernel, the same panic, regardless which device tree is used, including the meson-g12b-odroid-n2.dtb available in 5.3 source tree.

teacup · July 26, 2020 at 12:47 AM

Got inspired by

LibreELEC.tv/amlogic-0072-HACK-arm64-dts-meson-gx-add-ATF-BL32-reserved-memory.patch at 8939e00bd85d2323c9cb1d15c2834bc90d74e63f · chewitt/LibreELEC.tv · GitHub

and added the same reserved region into meson-g12-common.dtsi in kernel 5.7 tree, getting meson-g12b-gtking-pro.dtb, with which the kernel 5.1.5 could boot after all.

**chewitt** · July 26, 2020 at 5:50 AM Official Post

You should not expect to use device-tree files from 5.7 on 5.1, and I'm not sure what advantage you could perceive in doing that.

teacup · July 26, 2020 at 7:21 AM

I know, but when not having a suitable one for 5.1, then using one from 5.7 may be an option.

I still wonder though, why adding the reserved region helped, because it is not needed (and not present) with 5.7.

Most likely there must be some code in 5.7 skipping that region without that explicit setting in device tree.

Anyway, the point of all this has been to see if the older kernel (5.1) had the same errors as present with amlogic's 4.9 kernel:

9.2.2 DVB tbs driver / Hauppauge USB wintv dual HD / Tvheadend conflict - Hardware - CoreELEC Forums

in order to possibly find the fix in mainline to port it back to amlogic's 4.9.

Too bad the usb3 port works in 5.1 already, which seems to be the first version with some initial support for g12, so there is no opportunity to bisect the fix.