When Rockbox starts on my 5th generation 30 gig Video iPod, there are two clicks while the logo is displayed. It sounds like the heads are locked and unlocked, and it seems unnecessary. The initial lock is triggered when IDE0 is reset in system_init, and the unlock is when Rockbox tries to access the drive. If IDE0 isn't reset, there are no clicks and startup is a bit faster. I see no problems. Since the bootloader was just using IDE0, it should be in a reasonable state. A reset might be necessary if starting Rockbox from flash, but iPods can't do that now.
The same change may be possible for other pp502x based devices with hard drives.
What is the proper procedure to follow here? Should I have submitted a patch instead? Should I make it for other pp502x targets also, and say it needs testing on those? I can't say I know the hardware very well, and there might be a good reason why IDE0 should be reset. (Change is simple, DEV_RS = 0x3dfffef8 instead of 0x3ffffef8 in firmware/target/arm/system-pp502x.c
(edited: I meant pp502x not pp5002))