Re: [Intel-wired-lan] [PATCH iwl-next] idpf: preserve coalescing settings across resets

[Ahmed Zaki <ahmed.zaki@intel.com>]

On 2025-06-21 6:13 a.m., Simon Horman wrote:
> On Fri, Jun 20, 2025 at 11:15:48AM -0600, Ahmed Zaki wrote:
>> The IRQ coalescing config currently reside only inside struct
>> idpf_q_vector. However, all idpf_q_vector structs are de-allocated and
>> re-allocated during resets. This leads to user-set coalesce configuration
>> to be lost.
>>
>> Add new fields to struct idpf_vport_user_config_data to save the user
>> settings and re-apply them after reset.
>>
>> Reviewed-by: Madhu Chittim <madhu.chittim@intel.com>
>> Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
> 
> Hi Ahmed,
> 
> I am wondering if this patch also preserves coalescing settings in the case
> where.
> 
> 1. User sets coalescence for n queues
> 2. The number of queues is reduced, say to m (where m < n)
> 3. The user then increases the number of queues, say back to n
> 
> It seems to me that in this scenario it's reasonable to preserve
> the settings for queues 0 to m, bit not queues m + 1 to n.

Hi Simon,

I just did a quick test and it seems new settings are preserved in the 
above scenario: all n queues have the new coalescing settings.

> 
> But perhaps this point is orthogonal to this change.
> I am unsure.
> 

Agreed, but let me know if it is a showstopper.

Ahmed