[dpdk-dev] [dpdk-stable] [PATCH v2] net/mlx5: fix link status query

Ferruh Yigit ferruh.yigit at intel.com
Wed Feb 1 12:13:59 CET 2017


On 2/1/2017 9:07 AM, Adrien Mazarguil wrote:
> On Wed, Feb 01, 2017 at 06:53:55AM +0000, Shahaf Shuler wrote:
>> : Tuesday, January 31, 2017 6:17 PM, Ferruh Yigit:
>>> On 1/31/2017 11:45 AM, Shahaf Shuler wrote:
>>>> Trying to query the link status through new kernel ioctl API
>>>> ETHTOOL_GLINKSETTINGS was always failing due to kernel bug.
>>>> The bug was fixed on version 4.9
>>>> this patch uses the legacy ioctl API for lower kernels.
>>>>
>>>> Fixes: 188408719888 ("net/mlx5: fix support for newer link speeds")
>>>> CC: stable at dpdk.org
>>>>
>>>> Signed-off-by: Shahaf Shuler <shahafs at mellanox.com>
>>>> ---
>>>
>>> <...>
>>>
>>>> @@ -707,7 +708,7 @@ struct priv *
>>>>  static int
>>>>  mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int
>>>> wait_to_complete)  { -#ifdef ETHTOOL_GLINKSETTINGS
>>>> +#if KERNEL_VERSION(4, 9, 0) <= LINUX_VERSION_CODE
>>>
>>> Mostly it is not good idea to do kernel version check in the .c file.
>>>
>>> It is possible to move this comparison to the .h file, and set a feature
>>> macro based on comparison result, like HAVE_ETHTOOL_GLINKSETTINGS,
>>> and
>>> use this macro in the .c file.
>>>
>>> This makes .c code easier to understand. And the abstraction in the
>>> header file lets you update the comparison in the future without
>>> changing the code itself.
>>>
>>> But it is your call, do you prefer to continue with this one?
>>
>> This is a good suggestion. 
>> Adrien, Nélio what do you think?
> 
> Let's include this patch as-is. Doing so in a header file such as mlx5.h
> would require including linux/version.h from that file and cause the entire
> PMD to be even more OS-dependent.
> 
> We'll move this check elsewhere in the future if we need several such
> workarounds, thanks.

OK.

One more thing, comment log says:
"The bug was fixed on version 4.9"

And code does:
"+#if KERNEL_VERSION(4, 9, 0) <= LINUX_VERSION_CODE"

If the bug is fixed in 4.9, should check be "<" instead of "<="

> 
>>>>  	struct priv *priv = mlx5_get_priv(dev);
>>>>  	struct ethtool_link_settings edata = {
>>>>  		.cmd = ETHTOOL_GLINKSETTINGS,
>>> <...>
> 



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