Re: [PATCH] b43legacy: Fix machine check errors for PPC architecture with BCM4306/2

[Michael Buesch <mb@bu3sch.de>]

On Saturday 15 September 2007 20:07:22 Larry Finger wrote:
> Your comments may be correct; however, the fact remains that with a rev 4 BCM4306, the original code
> generates many, many machine checks on PPC architecture, and I get reads with all ones on i386
> indicating that the read is invalid. These all occur before the firmware is loaded. Making the
> "gmode" bit mimic the behavior of the phy_connected variable of bcm43xx gets rid of the problems on
> both platforms.

Sure. But if you workaround this like that, you could
as well get completely rid of the gmode bit, as you always force it on.
But I think that's not what we want. The real fix is simple. See below.

> The registers that error are not just the extended GPHY registers that caused 
> problems in the past, but all the PHY registers.

Nobody is talking about the extG registers.

> If you can suggest a reordering of the initialization that delays PHY setup until the "magic step"
> that eliminates this problem is done on/to the ssb backplane, I will be happy to test it. I was
> unable to find such a solution.

There is no reordering needed.
You just need to find out why phy->gmode was not set.
I think it's set based on the have_gphy and have_bphy bits.
So you need to look there why one of these is not set. That is the real
cause of the issue.

-- 
Greetings Michael.