Subject: Re: [PATCH net v3 2/2] igc: Modify the tx-usecs coalesce setting

From: Jakub Kicinski <[email-masked]>
Date: Wed, 6 Sep 2023 07:46:32 -0700

On Wed, 6 Sep 2023 02:52:30 +0000 Zulkifli, Muhammad Husaini wrote:
> > In the ioctl uAPI we can't differentiate between params which were echoed back
> > to us vs those user set via CLI to what they already were.
> > 
> > Maybe we should extend the uAPI and add a "queue pair" IRQ moderation?  
> 
> Good advice. BTW, if queue pair setting is enabled in the driver, could we change the existing ".supported_coalesce_params" for driver specific?
> 
> From:
> ETHTOOL_COALESCE_USECS which support (ETHTOOL_COALESCE_RX_USECS | ETHTOOL_COALESCE_TX_USECS)
> 
> To (new define):
> ETHTOOL_QUEUE_PAIR_COALESCE_USECS (ETHTOOL_COALESCE_RX_USECS)
> 
> With this, I believe user cannot set tx-usecs and will return error of unsupported parameters.

Do you mean change the .supported_coalesce_params at runtime?
I think so far we were expecting drivers to set flags for all types
they may support and then reject the settings incompatible with current
operation mode at the driver level.