Messages in this thread | | | From | (H. Peter Anvin) | Subject | Re: GGI Project Unhappy On Linux | Date | 28 Mar 1998 02:46:23 GMT |
| |
Followup to: <m1soo4cedq.fsf@flinx.npwt.net> By author: ebiederm+eric@npwt.net (Eric W. Biederman) In newsgroup: linux.dev.kernel > > HA> Actually, the people who designed VGA were actually very careful to > HA> *not* make this mistake (that had previously been made in EGA); > HA> unfortunately, some of the people that copied and extended their > HA> design weren't that careful. > > They were close except the index registers while resettable are not > readable. So you can rest it from a unknown state but you can 100% > reliably multitask access to the card. >
That is true, you have to use cli()..sti() or something to make the set index - write data or set index - read data atomic.
-hpa
-- PGP: 2047/2A960705 BA 03 D3 2C 14 A8 A8 BD 1E DF FE 69 EE 35 BD 74 See http://www.zytor.com/~hpa/ for web page and full PGP public key I am Bahá'í -- ask me about it or see http://www.bahai.org/ "To love another person is to see the face of God." -- Les Misérables
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu
| |