[Letux-kernel] [PATCH 00/20] A bunch of JZ4730 fixups for letux-kernel

[H. Nikolaus Schaller]

Hi Lubomir,

> Am 27.11.2020 um 04:13 schrieb Lubomir Rintel <lkundrak at v3.sk>:
> 
> On Thu, Nov 26, 2020 at 11:22:56PM +0100, Paul Boddie wrote:
>> On Thursday, 26 November 2020 20:06:12 CET H. Nikolaus Schaller wrote:
>>> Hi Paul and Lubomir,
>>> 
>>>> Paul<0001-Added-missing-TCU-declarations-for-the-JZ4730.patch>
>>> 
>>> a little late but you still deserve many thanks!
>>> 
>>> I have added it but see no difference. I just see Starting Kernel... and
>>> then some watchdog reboots.
>> 
>> One thing that may be different, at least when you can monitor the log, is the 
>> following line:
>> 
>>  [    0.000000] timer_probe: no matching timers found
>> 
>> Then again, searching for any reports about this leaves me unconvinced that it 
>> might be a problem. In Lubomir's log output, the next line is this...
>> 
>>  [    0.000000] sched_clock: 32 bits at 100 Hz, resolution 10000000ns, wraps 
>> every 21474836475000000ns
>> 
>> Maybe this indicates that the lack of timer assignments won't be a problem 
>> because scheduling is done using other timers.
> 
> Thank you. With a little more patching I got a more respectable panic
> now. I'll follow up with the patches.
> 
> The configuration [1] and dmesg [2] are here:
> 
> [1] https://people.freedesktop.org/~lkundrak/jz4730/config-20201127.txt

I have tried your config and found some issue in my wrapper script.
But still no dmesg or anything besides "Starting Kernel..." from U-Boot.

5218787 bytes read
## Booting image at 80600000 ...
   Image Name:   Linux-5.10.0-rc5+
   Image Type:   MIPS Linux Kernel Image (gzip compressed)
   Data Size:    5218723 Bytes =  5 MB
   Load Address: 80100000
   Entry Point:  8053f5b4
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK

Starting kernel ...

What I have not yet tried is to apply your latest set of patches.

> [2] https://people.freedesktop.org/~lkundrak/jz4730/dmesg-20201127.txt

Yours isn't much different:

Bytes transferred = 2849103 (2b794f hex)
## Booting kernel from Legacy Image at 81000000 ...
   Image Name:   Linux-5.9.0-rc1-letux-l400+
   Image Type:   MIPS Linux Kernel Image (gzip compressed)
   Data Size:    2849039 Bytes = 2.7 MiB
   Load Address: 80100000
   Entry Point:  80523aa0
   Verifying Checksum ... OK
   Uncompressing Kernel Image
[    0.000000] Linux version 5.10.0-rc4+ (lkundrak at demiurge.local) (mips64-linux-gnu-gcc (GCC) 10.2.1 

Now I wonder how we come to so much different kernel image sizes.

> 
> 1.) I'm using clk_ignore_unused because disabling of the dma clock seems
>    to make the cpu grind to a halt (not even jtag works at that point).
>    Also, if dma clock is kept enabled, disabling of some other clock
>    (no idea which one yet) makes things go very slow.
> 
> 2.) I'm using clocksource=jiffies because switch to ingenic-timer makes
>    the scheduler clock poll callback not fire and thus the clock ends
>    up loop aroud in 65535 ticks.
> 
> 3.) The scheduler clock poll doesn't probably run often enough because
>    the clock seems overflow and go backwards sometimes.
> 
> 4.) Some errors in LCD and DMA DT notes are now apparent and the MMC
>    doesn't work. I guess there might be more driver issues.
> 
> I'll be looking into above as time permits, but would be thankful for
> hints.

Well, as long as I don't see a dmesg I can't help much...

BR,
Nikolaus