[Soekris] Workaround for IDE hang after soft reset

[Martin K. Petersen]

As many of you have noticed the net5501 IDE controller doesn't fancy
coming back after a soft reset when it's been in DMA mode.  And unlike
CS5535, the CS5536 doesn't have a dedicated IDE controller reset
register.

As a quick workaround I added an MSR call to whack the companion chip
on the way out.  That did the trick and the net5501 found the disk
correctly during POST.

When I went to add this reset "the proper way" I found out that Linux
already has code to do this.  Apparently this is a known problem on
the CS5536.  Set CONFIG_X86_REBOOTFIXUPS=y in your .config and you're
all set.

BSD folks: The trick is to reboot by writing 0x1 to GLCP_SYS_RST (MSR
address 0x51700014) or DIVIL_SOFT_RESET (MSR address 0x51400017).


Martin