Re: [PATCH 1/1] pci: Block config access during BIST (resend)

Benjamin Herrenschmidt
2005-01-27T01:06:10Z

On Wed, 2005-01-26 at 10:34 -0600, Brian King wrote:

> Here is the last one. I've looked at making userspace sleep until BIST
> is finished. The downside I see to this is that is complicates the patch
> due to the following reasons:
>
> 1. In order to also make this work for Ben's PPC power management usage
> would require an additional flag and additional APIs to set and clear
> the flag.
> 2. Since BIST can be run at interrupt context, the interfaces to block
> and unblock userspace accesses across BIST must be callable from
> interrupt context. This prevents the usage of semaphores or simple
> wait_event macros and requires new macros that carefully check the new
> pci device flag and manage the spinlock.
>

Well, I honestly think that this is unnecessary burden. I think that
just dropping writes & returning data from the cache on reads is enough,
blocking userspace isn't necessary, but then, I may be wrong ;)

Ben.