On Thu, Apr 23, 2020 at 04:57:03PM +0200, Marcin Owsiany wrote: > TL;DR: My laptop starts ~20x slower than normal. Booting Debian hangs > before the kernel starts. Windows 10 boots slow, but then works fine.
Many thanks to everyone who responded! As usual, one can count on the Debian community! There is a new exciting (for me at least) development: I noticed, that in order to prevent this slowness, I just need to have some USB device plugged into any USB port while the laptop is starting! It does not need to be used, its mere presence helps. Also: - it does not matter which USB port, - it needs to be a device (I tried a flash drive and a headset, both help), a mere cable not connected to anything is not enough - an SD card inserted into the built-in reader is not enough either, - once booting nice and fast, it still goes slow as soon as I disconnect the device. The opposite is not true (while booting slow, connecting something has no effect). This seems to point blame at the USB controller? Perhaps it's flooding the CPU with interrupts for whatever reason? Some responses to the suggestions posted: David, thanks for your suggestion to try booting from a flash drive, this let me find the workaround :-) David and Kent, the computer is sealed (still on warranty) so I'd rather not take it apart just yet. It expires in a few days so I might try this soon, although USB controller does not seem to be something disconnectable easily (or rather, not connectable back easily :-) Alexis, as for memtest-ing, it seems like neither memtest86 nor memtest86+ seems to be able to start on this system, even with secure boot off. Perhaps these are not UEFI-compatible? Speaking of secure boot, I wonder why it keeps showing: Secure Boot Status: Disabled even though it's turned on: Secure Boot: Enabled I think both were enabled initially, but this changed around the time I upgraded BIOS. I did run the Lenovo diagnostics test tool for Windows though. It took several hours and the only warning had something to do with the RTC. The test was not eager to say what was wrong, it just displayed a warning sign next to "RTC". Alexander, I did install the latest available BIOS update. That did not help. I also reset the settings, to no effect either. FWIW, the model name is Lenovo ideapad FLEX 5-1570 (81CA0010US). More details are on the Information tab of the BIOS SETUP visible in the video. kind regards, -- Marcin Owsiany <mar...@owsiany.pl> http://marcin.owsiany.pl/ GnuPG: 4096R/CDFB68E9 59F4 A7DE D37D 95C5 8939 FDDB EFDE D44B CDFB 68E9