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

From: Benjamin Herrenschmidt
Date: Wed Apr 06 2005 - 17:49:22 EST


On Thu, 2005-04-07 at 00:35 +0200, Andreas Schwab wrote:
> Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> writes:
>
> > 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 ?
>
> Yes, it does. Without the sleep, switching is as fast as before.

It is weird tho. Could you try adding a printk or something to figure
out how much this is called during a typical swich ? It will seriously
spam your console though ... I would expect only 5 or 6 calls during a
normal switch (since the PLL value shouldn't change for a flat panel),
that is no more than maybe 50ms, while it seems you are having a much
bigger delay.

Ben.

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