[10:49] <luc4> Hello! I’d need to git bisect the kernel being used in the raspberry pi. I’m trying to follow the manuals, but I’m not sure I’m doing the right thing. I expected a debian/ dir to be in every commit, but it seems this commit, for instance, is not including it: https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux-raspi/+git/hirsute/tree/?id=84faf29b2d529a10cd71e609ddb237a5af8551a4. Is this the wrong git? Or maybe I should expect the debian/ 
[10:49] <luc4> not to be there? In that case can you point me to the proper manual to follow? Thanks!
[12:00] <juergh> @luc4, https://wiki.ubuntu.com/Kernel/BuildYourOwnKernel
[12:01] <juergh> luc4, ^^
[12:02] <juergh> bisecting a derivative is not trivial. especially raspi.
[12:14] <luc4> juergh: that is the page I’m referring to. The debian/ directory is needed, but I do not see it in many commits.
[12:15] <luc4> juergh: I can build with a regular “make”, but I guess I’m only building vmlinuz. Can I simply replace that in /boot/firmware in rpi? Can I ignore the initrd?
[12:16] <juergh> luc4, you can't build an Ubuntu kernel by simply running 'make'.
[12:17] <juergh> the raspi kernel is a derivative of the master (hirsute) kernel. we take the master hirsute kernel and but the raspi specific patches and configs on top of it.
[12:17] <juergh> you cant simply bisect. if you checkout a regular upstream commit than you don't have all the raspiness and that kernel will not boot at all.
[12:19] <luc4> juergh: I see, so I can’t bisect. Thank, at least I won’t try something that cannot be done :-)
[12:20] <juergh> luc4, it can be done but it's painful. why do you want to bisect? did you find a regression?
[12:22] <luc4> juergh: yes, usb issue: https://github.com/raspberrypi/linux/issues/3981
[12:22] <gitbot> raspberrypi issue 3981 in linux " RPi 4B, external HDD randomly freezes" [Open]
[12:27] <juergh> oh dear. this has been going on forever. and you're hitting this issue?
[12:28]  * ogra is entertained by people randomly adding and removing arm_64bit=1 to config.txt in that issue ...
[12:30] <luc4> juergh: yes, heavily. Sometimes 3 hours and the hd is gone.
[12:30] <juergh> ubuntu kernel? single or dual HDD? HDD or SSD?
[12:31] <luc4> juergh: I guess both ubuntu and raspberry os. I’m using ubuntu. What do you mean by single? HDD, not SSD.
[12:31]  * ogra would first try to add "usbcore.autosuspend=-1" to the kernel cmdline ... if there isnt traffic on the USB for a while when the system idles, the bus might go into suspend
[12:32] <juergh> some people have 2 HDDs attached.
[12:32] <luc4> juergh: I have 1. But I can plug up to 6, which is how I planned to bisect.
[12:33] <luc4> juergh: otherwise I may have to wait for days to reproduce.
[12:34] <juergh> luc4, what the HDD IO workload?
[12:34] <luc4> juergh: I could reproduce even on unmounted HDDs.
[12:34] <luc4> juergh: does not seem to be related to workload.
[12:36] <juergh> luc4, which Ubuntu kernels show this?
[12:36] <luc4> juergh: if not possible to bisect on Ubuntu nevermind, I’ll have to somehow switch to raspberry os, hoping it has a 64 bit version. Otherwise I won’t bisect :-)
[12:36] <luc4> juergh: I’m pretty sure 5.4 is not affected, 5.8 is.
[12:38] <juergh> luc4, you will have similar bisect issues with the raspi os kernel.
[12:38] <juergh> I'll see if I can reproduce this.
[12:39] <luc4> juergh: I’ll try. If impossible, I’ll give up.
[12:39] <luc4> juergh: thanks!
[12:39] <juergh> luc4, and your HDD is externally powered I assume?
[12:40] <luc4> juergh: yes, it is.
[12:46] <luc4> ogra, juergh: I missed the advice. I already tried to disable autosuspend in proc. I could still reproduce.
[12:46] <ogra> k. was just a thought