17:54 <gpiccoli> Hey folks! Did anybody see issues when running with ftrace on dragonboard 820c ?

17:54 <gpiccoli> specially after kernel 5.7 ...

17:57 <bamse> gpiccoli: what's the issue you're seeing?

17:57 <gpiccoli> o/ bamse - I can't boot the board

17:57 <gpiccoli> Not even with earlycon - I see nothing

17:58 <bamse> so your kernel boots unless you enable CONFIG_FUNCTION_TRACE?

17:58 <gpiccoli> I've bisected and found the responsible commits...I'm trying to understand *why* they're an issue for me, but not for multiple people

17:58 <gpiccoli> bamse, yes, and I'm adding the DYNAMIC_FTRACE stuff as well

17:58 <gpiccoli> I didn't test without the dynamic paraphernalia heheh

17:59 <gpiccoli> the responsible commit is this one - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cfa7ede20f1

17:59 <gpiccoli> just setting TEXT_OFFSET to 0x0 broke my setup

17:59 <gpiccoli> but..only with ftrace! I could boot up to 5.15rc3 without ftrace hehe

17:59 <gpiccoli> I'm not sure if it might be related to the bootloader, I'm kinda new to ARM

18:00 <gpiccoli> BTW, ftrace is part of my investigation about the gpu thing you suggested me on ML =)

18:00 <bamse> hmm, i've used ftrace after 5.7 on that board...

18:05 <gpiccoli> that's very weird! I'm using Inforce 6640 - it's a board based on db820c

18:06 <gpiccoli> Also, let me take the opportunity to ask you that bamse - I'm working a DT patch for this board...the reason is that the current dts allows only booting with UFS and serial, it's very limited. If I use the dts from db820c I can boot the board flawlessly, with all peripherals, like ethernet, SD, seems BT is also working, GPU

18:07 <gpiccoli> What is the best way to "fix" that? Just add the ifc6640 to dbc dts as compatible, or update the ifc6640.dts to match db820c?

18:10 <bamse> there's some differences between the boards, so there should be two dts files, each one describing the particular board

18:10 <bamse> but you can very well extend ifc6640.dts by "cherry picking" things from the db820c dts

18:11 <gpiccoli> ok, perfect! that's my goal, to extend the dts file including the missing pieces from db820c

18:11 <gpiccoli> tnx for the suggestion !

18:12 <bamse> i presume you have the schematics or data sheet...so try to go through all the components and use the names from the documentation and wire things up properly

18:12 <bamse> using db820c.dts as a reference

18:36 <gpiccoli> hmm..yeah, I have some documentation, but i'm not sure it is so detailed as dragonboard schematics, which is incredibly comprehensive