Re: [PATCH] radeonfb: (#2) Implement proper workarounds for PLL accesses

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2005-04-05 at 23:44 +0200, Andreas Schwab wrote:
> Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:
> 
> > After discussion with ATIs, it seems that the workarounds they initially
> > gave me were not completely correct.
> >
> > This patch implements the proper ones, which includes sleeping in PLL
> > accesses, and thus requires the previous patch to make sure we do not
> > call unblank at interrupt time (unless oops_in_progress is set, in which
> > case I use an mdelay).
> >
> > It also removes obsolete code that used to disable some power management
> > features in the accel init code.
> 
> This patch does no good on Radeon M6 (iBook G3).  It makes mode switching
> to take an extraordinary amount of time, ie. when switching away from X it
> takes about 2-3 seconds until the console is restored.

Hrm... it should only add a few ms, maybe about 20 ms to the mode
switching... If you remove the radeon_msleep(5) call from the
radeon_pll_errata_after_data() routine in radeonfb.h, does it make a
difference ?

Ben.