Re: [PATCH V7 net-next 02/11] net/mlx5: Implement cqe_compress_type via devlink params

[Daniel Zahka <daniel.zahka@gmail.com>]

On 9/6/25 9:29 PM, Saeed Mahameed wrote:
> From: Saeed Mahameed <saeedm@nvidia.com>
>
> Selects which algorithm should be used by the NIC in order to decide rate of
> CQE compression dependeng on PCIe bus conditions.
>
> Supported values:
>
> 1) balanced, merges fewer CQEs, resulting in a moderate compression ratio
>     but maintaining a balance between bandwidth savings and performance
> 2) aggressive, merges more CQEs into a single entry, achieving a higher
>     compression rate and maximizing performance, particularly under high
>     traffic loads.
>

Hello,

I'm facing some issues when trying to use the devlink param introduced 
in this patch. I have a multihost system with two hosts per CX7.

My NIC is:
$ lshw -C net
   *-network
        description: Ethernet interface
        product: MT2910 Family [ConnectX-7]
        vendor: Mellanox Technologies

My fw version is: 28.43.1014

To reproduce the problem I simply read the current cqe_compress_type 
setting and then change it:

$ devlink dev param show pci/0000:56:00.0 name cqe_compress_type
pci/0000:56:00.0:
   name cqe_compress_type type driver-specific
     values:
       cmode permanent value balanced

$ devlink dev param set pci/0000:56:00.0 name cqe_compress_type value 
"aggressive" cmode permanent
kernel answers: Connection timed out

from dmesg:
[  257.111349] mlx5_core 0000:56:00.0: 
wait_func_handle_exec_timeout:1159:(pid 72061): cmd[0]: 
ACCESS_REG(0x805) No done completion
[  257.137072] mlx5_core 0000:56:00.0: wait_func:1189:(pid 72061): 
ACCESS_REG(0x805) timeout. Will cause a leak of a command resource
[  270.871521] mlx5_core 0000:56:00.0: mlx5_cmd_comp_handler:1709:(pid 
0): Command completion arrived after timeout (entry idx = 0).


subsequent attempts to use mstfwreset hang:

$ ./mstfwreset -y -d 56:00.0 reset
-E- Failed to send Register MFRL: Timed out trying to take the ICMD 
semaphore (520).

I can toggle the parameter ok using the mstconfig binary built from the 
mstflint github repo.

Let me know if I can provide any more information.

Daniel