[PATCH] Do not trap access to timer and keyboard

Samuel Thibault samuel.thibault at ens-lyon.org
Wed Mar 17 15:26:19 PDT 2010

Adam Jackson, le Wed 17 Mar 2010 17:44:34 -0400, a écrit :
> On Sat, 2010-03-13 at 02:26 +0100, Samuel Thibault wrote:
> > -    ioperm(0x40,4,0); /* trap access to the timer chip */
> > -    ioperm(0x60,4,0); /* trap access to the keyboard controller */
> I'm not sold on this.  You really do not want to be bashing these ports
> directly if the kernel also is.

Sure. The issue is that some VESA BIOS do need it.

> If this _is_ right, then it almost certainly needs to be done for all
> platforms.

Well, actually only Linux and Hurd used to do it. Since Linux also
set iopl to 3 to be able to access to ports >= 0x400, the I/O bitmask
set by ioperm() is just completely ignored, and the same two lines in
the Linux code don't have any effect.

> Do you have a link to a bug that this is solving?



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