Subject: Re: [PATCH net] ice: check whether AUX devices/drivers are supported in ice_rebuild

From: Leon Romanovsky <[email-masked]>
Date: Sun, 5 Sep 2021 10:23:36 +0300

On Fri, Sep 03, 2021 at 09:25:00AM +0800, Yongxin Liu wrote:
> In ice_rebuild(), check whether AUX devices/drivers are supported or not
> before calling ice_plug_aux_dev().
> 
> Fix the following call trace, if RDMA functionality is not available.
> 
>   auxiliary ice.roce.0: adding auxiliary device failed!: -17
>   sysfs: cannot create duplicate filename '/bus/auxiliary/devices/ice.roce.0'
>   Workqueue: ice ice_service_task [ice]
>   Call Trace:
>    dump_stack_lvl+0x38/0x49
>    dump_stack+0x10/0x12
>    sysfs_warn_dup+0x5b/0x70
>    sysfs_do_create_link_sd.isra.2+0xc8/0xd0
>    sysfs_create_link+0x25/0x40
>    bus_add_device+0x6d/0x110
>    device_add+0x49d/0x940
>    ? _printk+0x52/0x6e
>    ? _printk+0x52/0x6e
>    __auxiliary_device_add+0x60/0xc0
>    ice_plug_aux_dev+0xd3/0xf0 [ice]
>    ice_rebuild+0x27d/0x510 [ice]
>    ice_do_reset+0x51/0xe0 [ice]
>    ice_service_task+0x108/0xe70 [ice]
>    ? __switch_to+0x13b/0x510
>    process_one_work+0x1de/0x420
>    ? apply_wqattrs_cleanup+0xc0/0xc0
>    worker_thread+0x34/0x400
>    ? apply_wqattrs_cleanup+0xc0/0xc0
>    kthread+0x14d/0x180
>    ? set_kthread_struct+0x40/0x40
>    ret_from_fork+0x1f/0x30
> 
> Fixes: f9f5301e7e2d ("ice: Register auxiliary device to provide RDMA")
> Signed-off-by: Yongxin Liu <[email-masked]>
> ---
>  drivers/net/ethernet/intel/ice/ice_main.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
> index 0d6c143f6653..98cc708e9517 100644
> --- a/drivers/net/ethernet/intel/ice/ice_main.c
> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> @@ -6466,7 +6466,9 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
>  	/* if we get here, reset flow is successful */
>  	clear_bit(ICE_RESET_FAILED, pf->state);
>  
> -	ice_plug_aux_dev(pf);
> +	if (ice_is_aux_ena(pf))
> +		ice_plug_aux_dev(pf);
> +

The change is ok, but it hints that auxiliary bus is used horribly wrong
in this driver. In proper implementation, which should rely on driver/core,
every subdriver like ice.eth, ice.roce e.t.c is supposed to be retriggered
by the code and shouldn't  ave "if (ice_is_aux_ena(pf))" checks.

Thanks

>  	return;
>  err_vsi_rebuild:
> -- 
> 2.14.5