The HyperNews Linux KHG Discussion Pages

sti() called too late.

Forum: The Linux Kernel Hackers' Guide
Re: Sad sti() called too late. (Erik Thiele)
Keywords: cli() IRQ rtc realtime timer lost
Date: Fri, 24 Jan 1997 19:07:40 GMT
From: Gadi Oxman <>

Unfortunately, some combinations of chipsets, IDE
interfaces and drives will not work reliably when
interrupts are allowed to occur while we are servicing
a disk interrupt.

The IDE driver can optionally unmask interrupts during
the data transfer, by using "hdparm -u1 /dev/hdx".

This is a typical problem; on the one hand, we want to
achieve the best possible performance, but once we do
this, we might find out that we are no longer compatible
with marginal hardware which could have worked if only
we didn't try to push it so hard.

Gadi Oxman