Re: [PATCH 11/16] libata-eh-fw: implement new EH scheduling via timeout

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
> Here is another method to deal with it as adding ->timeout_autopsy or 
> anything similar is too unattractive.  A new interface, say, 
> ata_eh_thaw_port() can be implemented which thaws the port without 
> resetting it.  Then, in BMDMA autopsy, after determining that a timeout 
> was caused by DMA error, it can thaw the port and adjust qc->err_mask to 
> AC_ERR_HOST_BUS.  How does it sound to you?

Seems rational.


>> Get the user back up and talking to their disk as fast as possible.
> 
> Command timeout is 30 secs (which, I think is a bit too long for ATA 
> disk devices).  If resetting succeeds, it takes less than two seconds. I 
> don't think it will make any difference to the user.

Well overall I want to minimize the change from existing behavior, since 
there is enough change as it is.  In current libata and drivers/ide, it 
can continue after a properly indicated DMA error without doing a reset.

And I just think its rude, to reset hardware when it doesn't need 
resetting.  Its sorta like the Windows mentality -- "just reboot it, 
that will fix stuff"  Linux shouldn't be rude to hardware, when it need 
not be :)

	Jeff