Re: [PATCH 1/2] I/OAT: Add watchdog/reset functionality to ioatdmadriver

From: Brice Goglin
Date: Mon Jul 14 2008 - 10:17:58 EST


Maciej Sosnowski wrote:
> Due to occasional DMA channel hangs observed for I/OAT versions 1.2 and 2.0
> a watchdog has been introduced to check every 2 seconds
> if all channels progress normally.
> If stuck channel is detected, driver resets it.
> The reset is done in two parts. The second part is scheduled
> by the first one to reinitialize the channel after the restart.
>

Is all this transparent to the caller? Are you reposting all copies to
the hardware after the reset? Or are we going to get some DMA_ERROR
return values ?

> Sleep time in self_test has been increased to 10ms
> since in some cases 1ms appeared not to be enough

Thanks Maciej, this helps a lot here.

Brice

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