Re: [net-next 02/15] ethtool: Add support for configuring PFC stall prevention in ethtool

[Gal Pressman <galp@mellanox.com>]

On 24-Mar-18 17:57, Andrew Lunn wrote:
> On Fri, Mar 23, 2018 at 03:39:12PM -0700, Saeed Mahameed wrote:
>> From: Inbar Karmy <inbark@mellanox.com>
>>
>> In the event where the device unexpectedly becomes unresponsive
>> for a long period of time, flow control mechanism may propagate
>> pause frames which will cause congestion spreading to the entire
>> network.
>> To prevent this scenario, when the device is stalled for a period
>> longer than a pre-configured timeout, flow control mechanisms are
>> automatically disabled.
>>
>> This patch adds support for the ETHTOOL_PFC_STALL_PREVENTION
>> as a tunable.
>> This API provides support for configuring flow control storm prevention
>> timeout (msec).
>>
>> Signed-off-by: Inbar Karmy <inbark@mellanox.com>
>> Cc: Michal Kubecek <mkubecek@suse.cz>
>> Cc: Andrew Lunn <andrew@lunn.ch>
>> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
>> ---
>>  include/uapi/linux/ethtool.h | 4 ++++
>>  net/core/ethtool.c           | 6 ++++++
>>  2 files changed, 10 insertions(+)
>>
>> diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
>> index 20da156aaf64..9dc63a14a747 100644
>> --- a/include/uapi/linux/ethtool.h
>> +++ b/include/uapi/linux/ethtool.h
>> @@ -217,10 +217,14 @@ struct ethtool_value {
>>  	__u32	data;
>>  };
>>  
>> +#define PFC_STORM_PREVENTION_AUTO	0xffff
>> +#define PFC_STORM_PREVENTION_DISABLE	0
>> +
>>  enum tunable_id {
>>  	ETHTOOL_ID_UNSPEC,
>>  	ETHTOOL_RX_COPYBREAK,
>>  	ETHTOOL_TX_COPYBREAK,
>> +	ETHTOOL_PFC_PREVENTION_TOUT,
> 
> Hi Inbar
> 
> Please could you add a comment here about the units. Ideally we want
> this file to be self documenting.

Thank you for the review, we will fix that.

> 
>      Andrew
>