busmaster/latency for video

[Geert Uytterhoeven]

On Thu, 7 Oct 1999, Michel Lanners wrote:
> On   6 Oct, this message from Ryan Nielsen echoed through cyberspace:
> > PCI_COMMAND_MASTER is not enabled and latency = 0 for the ultimate rez video card, and pci_write_config_*
> > do not change them. latency = 32 and mastering is enabled for all the other cards in the machine,
> > 
> > should they be enabled ?
> 
> That probably means the card doesn't support them.
> 
> Normal graphic cards have no need for mastership. Only those with video
> inputs need it, in order to transfer video data into the framebuffer
> without CPU help.

Many recent graphics chips to support bus mastering, especially the AGP ones.

Greetings,

						Geert

--
Geert Uytterhoeven ----------------- Sony Suprastructure Center Europe (SUPC-E)
Geert.Uytterhoeven at sonycom.com ------------------- Sint Stevens Woluwestraat 55
Phone +32-2-7248632 Fax +32-2-7262686 ---------------- B-1130 Brussels, Belgium


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/