lkml.org 
[lkml]   [2002]   [Aug]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Passing kernel parameters
> Unfortunately this is not working.  dmesg for ide still shows the following:
> ide: Assuming 33MHz system bus speed for PIO modes; override with
> idebus=xx
>
> despite the fact that I've specified 'idebus=66' and the following lines note:
>
> VP_IDE: VIA vt82c596b (rev 12) IDE UDMA66 controller on pci00:07.1

note that it says *system* bus speed. that is, the clock fed to the IDE
controller (usually the PCI clock, 33 MHz). this is NOT the transfer mode!

by lying to the driver that "idebus=66", all you accomplish is making your
transfers half the speed they should be. the driver says
"since the clock period is 15ns, and I want (say) udma33
(16b every 60ns), I'll tell the controler to do 16b every 4 clocks."

alas, the real period is 30ns, so you get 16b every 120ns. voila, udma16 ;(

summary: don't lie to the driver; the default is probably correct.

regards, mark hahn.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:28    [W:0.020 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site