[dpdk-dev] ***Spam*** Re: [RFC 02/14] virtio: use eth_link_read/write (and bug fix)

[Andrew Rybchenko]

On 07/17/2017 07:01 PM, Stephen Hemminger wrote:
> On Sun, 16 Jul 2017 15:33:26 +0300
> Andrew Rybchenko <arybchenko at solarflare.com> wrote:
>
>>> +	link.link_autoneg = ETH_LINK_SPEED_FIXED;
>> As I understand link_autoneg is 1 bit field with boolean semantics. I.e. 0/false - no autoneg, 1/true - autoneg.
>> It looks like it has wrong comment:
>>           uint16_t link_autoneg : 1;  /**< ETH_LINK_SPEED_[AUTONEG/FIXED] */
>>
>> since
>> #define ETH_LINK_SPEED_AUTONEG  (0 <<  0)  /**< Autonegotiate (all speeds) */
>> #define ETH_LINK_SPEED_FIXED    (1 <<  0)  /**< Disable autoneg (fixed speed) */
>>
>> whereas
>> #define ETH_LINK_FIXED          0 /**< No autonegotiation. */
>> #define ETH_LINK_AUTONEG        1 /**< Autonegotiated. */
>>
>> In general this attempt to introduce bug is the result of wrong comment which is caused by very similar
>> defines with opposite values.
> Orignal observation was because some drivers (vmxnet3) were setting autoneg = fixed
> and others were not. Turns out it makes no difference
> since FIXED == 0, the old code and new code have same effect.

May be I miss something, but  ETH_LINK_SPEED_FIXED==1, but 
ETH_LINK_FIXED==0.
So, initially it was 0 (fixed speed), but now it is 1 (autoneg).