Re: Safety of IRQ during i/o

[Pete Zaitcev]

>[...]
> I would think that this would be safe when using DMA, and likely to be
> safe for PIO and more recent chipsets, but I wouldn't want to actually
> tell anyone that.

A little story from OLS. I have a 486/75 laptop, which can only
do PIO. It always was losing characters evern on 9600 baud on its
serial port, and I thought it was simply broken for five years.
A guy who did a security talk showed me that doing hdparm -u
fixes the problem. Apparently, the lappy has a non-buffering UART.

So, it seems that hdparm -u is a very useful thing for obsotele
boxes. If you do DMA, you probably do not care.

-- Pete