Re: 2.4.9-ac10 IDE access slows as uptime increases

Steve Maughan (
Sat, 29 Sep 2001 20:27:52 +0100

* Alan Cox ( wrote:
> Second question is what is in your IDE logs. The IDE layer will change
> down speeds when it hits a repeated problem (eg a DMA timeout) so if
> need be will switch back to PIO or to MWDMA.

I have what sounds like a similar problem - assuming it is a problem
with the IDE layer dropping the speed - except mine is with my CD or
DVD drive. They run a lot slower under the 2.4.x kernels than under
2.2.19 (looking at 2-3megs/s under 2.4.x, 5-7megs/s under 2.2.19).

Also when using 2.4.x, the kernel has a habit of disabling DMA and
performance plummets. Yet it is fine with 2.2.19.

Is this a related issue? Is there a fix for this?

Steve Maughan
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at