RE: [PATCH 1/2] I/OAT: Add watchdog/reset functionality to ioatdma driver

Brice Goglin wrote:

Maciej Sosnowski wrote:

quoted

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 ?

Yes, it is transparent.
The driver should take care of all the descriptors
that have not been served before the reset.

quoted

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.

Sure.

Brice

Regards,
Maciej