[Intel-wired-lan] [PATCH iwl-next v4 2/2] igc: Change Tx mode for MQPRIO offloading

[Simon Horman]

On Fri, Mar 21, 2025 at 02:52:39PM +0100, Kurt Kanzenbach wrote:
> The current MQPRIO offload implementation uses the legacy TSN Tx mode. In
> this mode the hardware uses four packet buffers and considers queue
> priorities.
> 
> In order to harmonize the TAPRIO implementation with MQPRIO, switch to the
> regular TSN Tx mode. This mode also uses four packet buffers and considers
> queue priorities. In addition to the legacy mode, transmission is always
> coupled to Qbv. The driver already has mechanisms to use a dummy schedule
> of 1 second with all gates open for ETF. Simply use this for MQPRIO too.
> 
> This reduces code and makes it easier to add support for frame preemption
> later.
> 
> Tested on i225 with real time application using high priority queue, iperf3
> using low priority queue and network TAP device.
> 
> Acked-by: Faizal Rahim <faizal.abdul.rahim at linux.intel.com>
> Signed-off-by: Kurt Kanzenbach <kurt at linutronix.de>

Reviewed-by: Simon Horman <horms at kernel.org>