Not all DMA transfer finishes in finite time. When I have enabled
picture feed to videoram on LML33 I have here in my dual AMD, nothing
is going to stop transfer: it will happilly feed data during soft
reboot. Either computer will refuse to boot completely because of
videobios will not be able to initialize videoram (Hey, you have
with no usable video memory, all write-verify cycles failed: returned
data differ from written one. Please add some memory chips...),
or you'll see garbage on screen until device's busmastering bit
is disabled (when LML33 driver is loaded...).
Only problem is when you are going to disable busmastering: like
we have early printk console, we need its counterpart on shutdown,
as PCI video drivers can be unloaded long before other drivers finish
unloading (== poweroff does not work on my system for some time.
I assume that it oopses somewhere after matroxfb shutdown), and
after shutting down PCI-AGP bridge no message can find its way to
the screen, even with any early printk solution...
Best regards,
Petr Vandrovec
vandrove@vc.cvut.cz
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