PSP: Pressing the menu combo often hangs

Description

While in a core, pressing the menu combo button(s) to return to the menu will often instead cause RetroArch to completely freeze. The screen still shows the core but it will be frozen. The only option is to press the PSP home button and completely exit RetroArch; no other buttons work.

This happens to me on average once every play session of ~30 minutes. The only times it occured while I was doing development, I didn't have any breakpoints set and Ctrl+C in gdb wasn't able to stop the process, so I'm not sure at what point in the code this is happening. Maybe some kind of race condition?

Expected behavior

RetroArch should switch to the menu.

Actual behavior

RetroArch stays frozen at the core.

Steps to reproduce the bug

Unfortunately I haven't been able to consistently reproduce this. The best way to reproduce is to play for 30 minutes or so and return to the menu frequently. Save state spamming helps :)

Bisect Results

N/A

Version/Commit

You can find this information under Information/System Information

• RetroArch: 1.8.4 (but this has been happening as far as I can remember, at least back until 1.7.7)

Environment information

• OS: PSP
• Compiler: gcc

Thanks!

Start with the PSP menu-combination handling and the path taken when returning from a core to the menu; the issue provides no file or test entry point. Use a debugger while repeatedly switching menus during extended play, and consider the report resolved only when the menu combo consistently returns to the menu without freezing.