Re: [PATCH iwl-net v5] igc: Expose tx-usecs coalesce setting to user

["naamax.meir" <naamax.meir@linux.intel.com>]

On 9/8/2023 11:17, Muhammad Husaini Zulkifli wrote:
> When users attempt to obtain the coalesce setting using the
> ethtool command, current code always returns 0 for tx-usecs.
> This is because I225/6 always uses a queue pair setting, hence
> tx_coalesce_usecs does not return a value during the
> igc_ethtool_get_coalesce() callback process. The pair queue
> condition checking in igc_ethtool_get_coalesce() is removed by
> this patch so that the user gets information of the value of tx-usecs.
> 
> Even if i225/6 is using queue pair setting, there is no harm in
> notifying the user of the tx-usecs. The implementation of the current
> code may have previously been a copy of the legacy code i210.
> Since I225 has the queue pair setting enabled, tx-usecs will always adhere
> to the user-set rx-usecs value. An error message will appear when the user
> attempts to set the tx-usecs value for the input parameters because,
> by default, they should only set the rx-usecs value.
> 
> This patch also adds the helper function to get the
> previous rx coalesce value similar to tx coalesce.
> 
> How to test:
> User can get the coalesce value using ethtool command.
> 
> Example command:
> Get: ethtool -c <interface>
> 
> Previous output:
> 
> rx-usecs: 3
> rx-frames: n/a
> rx-usecs-irq: n/a
> rx-frames-irq: n/a
> 
> tx-usecs: 0
> tx-frames: n/a
> tx-usecs-irq: n/a
> tx-frames-irq: n/a
> 
> New output:
> 
> rx-usecs: 3
> rx-frames: n/a
> rx-usecs-irq: n/a
> rx-frames-irq: n/a
> 
> tx-usecs: 3
> tx-frames: n/a
> tx-usecs-irq: n/a
> tx-frames-irq: n/a
> 
> Fixes: 8c5ad0dae93c ("igc: Add ethtool support")
> Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
> Tested-by: Naama Meir <naamax.meir@linux.intel.com>
> ---
> V4 -> V5:
> - Squash patch for set/get together as recommended by Jakub.
> - Fix unstabilize value when user insert both tx and rx params
> together.
> - Add error message for unsupported config.
> 
> V3 -> V4:
> - Implement the helper function, as recommended by Brett Creely.
> - Fix typo in cover letter.
> 
> V2 -> V3:
> - Refactor the code, as Simon suggested, to make it more readable.
> 
> V1 -> V2:
> - Split the patch file into two, like Anthony suggested.
> ---
>   drivers/net/ethernet/intel/igc/igc_ethtool.c | 31 ++++++++++++--------
>   1 file changed, 19 insertions(+), 12 deletions(-)

Tested-by: Naama Meir <naamax.meir@linux.intel.com>