Re: [Openocd-development] adapter_khz ...

[David B. <da...@pa...>]

On Thursday 25 March 2010, Laurent Gauch wrote:
> David Brownell wrote:
> > On Thursday 25 March 2010, Laurent Gauch wrote:
> >   
> >>  ... OK, but we do not resolve the problem by DON'T DO THAT!!
> >>
> >> Actually there are a lot of target scripts working with JTAGkey but not 
> >> with JTAGkey-2, 

> > Specifically which ones?
> >   
> 
> Amontec customers feedback this troubles on
> 
> target/pxa270.cfg
> target/sam7se512.cfg
> target/samsung_s3c2440.cfg
> target/netx500.cfg
> ...

hose dsn't even touch clocking, so the issue must be
the gratuitous driver incompatibility you've introduced
(with default clocking of jtagkey-2 much faster).

That is ... the *incompatibility* is from your driver.

While the root cause is clearly customer setups relying
on random driver state in the first place.  "Don't do
that".  There's a reason why you're supposed to initialize
hardware before relying on it to act initialized...


> target/pxa255.cfg

That one defaults the clock to a safe 300 KHz.  SO if that fails,
eeither (a) there's another bug in your driver, or (b)
there's some other bug (unrelated):

 # PXA255 comes out of reset using 3.6864 MHz oscillator.
 # Until the PLL kicks in, keep the JTAG clock slow enough
 # that we get no errors.
 adapter_khz 300
 $_TARGETNAME configure -event "reset-start" { adapter_khz 300 }

Innocuous.