Re: [PATCH] cxl: Flush PSL cache before resetting the adapter

[Frederic Barrat <fbarrat@linux.vnet.ibm.com>]

Hi Vaibhav,


Le 04/10/2016 à 07:49, Vaibhav Jain a écrit :
> Hi Fred,
>
> Frederic Barrat <fbarrat@linux.vnet.ibm.com> writes:
>
>>
>> +	/* the adapter is about to be reset, so ignore errors */
>> +	cxl_data_cache_flush(adapter);
>> +
> Will be a good idea if we return error and not let the reset to proceed,
> if cxl_data_cache_flush returns EBUSY as continuing again may cause the
> UE error.

I'm going to change cxl_data_cache_flush() to return ETIMEOUT instead of 
EBUSY, as it is misleading. With the current patch, EBUSY is not 
returned because there are active contexts running on the card. It is 
returned when the hardware/psl doesn't reply within 5 seconds to the 
flush request. It's not supposed to happen and would show an issue with 
the hardware/psl. In which case the adapter is close to useless, so we 
might as well try resetting it.

On a related note, we've talked with the folks from cxlflash, and we'll 
test a separate (complementary) patch to deny resetting the adapter if 
there are any active contexts, since, as you say, the likelihood of 
hitting a UE would be pretty high.

   Fred