SCC chip bug on various macs

[Takashi Oe]

Hi,

According to Darwin's SCC driver, there is a chip bug in that the receiver
may lock up when certain conditions are met.  The affected machines listed
in the driver source are:

Performa 5400/6400/6500, 20th Anniversary Mac, PowerBook 2400/3400,
StarMax 3000, PowerMac 4400, Power Macintosh G3 (Gossamer).

The workaround is in FixZeroBug() of Darwin source:

IO/Drivers/Port/AppleSCCSerial/AppleSCCSerial.kmodproj/SccChipPrimatives.cpp

Last I checked, this workaround is not in Linux's
drivers/macintosh/macserial.c, and I suspect this bug might account for
occassional failure reports with mac serial.

Anybody care to code it for Linux?  I would do it if I had any of the
affected machine, but I don't, so .... anybody?  :)


Cheers,

Takashi Oe


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