Re: [PATCH/RFC] I/O-check interface for driver's error handling

Benjamin Herrenschmidt
2005-03-05T05:50:02Z

On Fri, 2005-03-04 at 23:57 +0100, Pavel Machek wrote:

> What prevents driver from being run on another CPU, maybe just doing
> mdelay() between hardware accesses?

Almost all drivers that I know have some sort of locking. Nothing nasty
about it. Besides, you can't expect everything to be as simple as
putting two bit of lego together, the problem isn't simple.

If an IOs gets there out of sync, it's a non-issue, it will most
probably just return all 1's, and if using Seto proposed functions, the
bit of code doing it will "know" there was an error and will stop.

But a driver notified of errors that, typically, triggered a slot
isolation like on pSeries, will have to wait for all IOs to complete
anyway, stop everything, so that the slot can be reset.

I think you are raising a non-issue.

Ben.