Re: [PATCH] hv: utils: properly pick TS protocol version for future hosts

[Vitaly Kuznetsov <vkuznets@redhat.com>]

"Alex Ng (LIS)" <alexng@microsoft.com> writes:

>> -----Original Message-----
>> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
>> Sent: Monday, November 28, 2016 8:30 AM
>> To: devel@linuxdriverproject.org
>> Cc: linux-kernel@vger.kernel.org; KY Srinivasan <kys@microsoft.com>;
>> Haiyang Zhang <haiyangz@microsoft.com>; Alex Ng (LIS)
>> <alexng@microsoft.com>
>> Subject: [PATCH] hv: utils: properly pick TS protocol version for future hosts
>> 
>> It is reasonable to expect that future Hyper-V versions will continue
>> supporting TimeSync v4 protocol, we, however, only pick it for
>> VERSION_WIN10. Currently this is not an issue as VERSION_WIN10 is the
>> maximum protocol version we can negotiate but this may change in future.
>> Instead of hoping that we won't forget to update it when time comes I
>> suggest we change the default now.
>> 
>
> Vitaly, can you see if this upstream commit already fixes the issue you described?
>
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/drivers/hv?id=3da0401b4d0e17aea7526db0235d98fa535d903e
>

Yes, thanks, missied it!

>> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>> ---
>>  drivers/hv/hv_util.c | 13 +++++--------
>>  1 file changed, 5 insertions(+), 8 deletions(-)
>> 
>> diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
>> index bcd0630..a13003f 100644
>> --- a/drivers/hv/hv_util.c
>> +++ b/drivers/hv/hv_util.c
>> @@ -382,23 +382,20 @@ static int util_probe(struct hv_device *dev,
>>  	 * Based on the host; initialize the framework and
>>  	 * service version numbers we will negotiate.
>>  	 */
>> -	switch (vmbus_proto_version) {
>> -	case (VERSION_WS2008):
>> +	if (vmbus_proto_version <= VERSION_WS2008) {
>>  		util_fw_version = UTIL_WS2K8_FW_VERSION;
>>  		sd_srv_version = SD_VERSION_1;
>>  		ts_srv_version = TS_VERSION_1;
>>  		hb_srv_version = HB_VERSION_1;
>> -		break;
>> -	case(VERSION_WIN10):
>> +	} else if (vmbus_proto_version < VERSION_WIN10) {
>>  		util_fw_version = UTIL_FW_VERSION;
>>  		sd_srv_version = SD_VERSION;
>> -		ts_srv_version = TS_VERSION;
>> +		ts_srv_version = TS_VERSION_3;
>>  		hb_srv_version = HB_VERSION;
>> -		break;
>> -	default:
>> +	} else {
>>  		util_fw_version = UTIL_FW_VERSION;
>>  		sd_srv_version = SD_VERSION;
>> -		ts_srv_version = TS_VERSION_3;
>> +		ts_srv_version = TS_VERSION;
>>  		hb_srv_version = HB_VERSION;
>>  	}
>> 
>> --
>> 2.9.3

-- 
  Vitaly