Re: [PATCH iwl-net] ice: fix infinite recursion in ice_cfg_tx_topo via ice_init_dev_hw

[Jacob Keller <jacob.e.keller@intel.com>]

On 4/13/2026 12:14 PM, Petr Oros wrote:
> On certain E810 configurations where firmware supports Tx scheduler
> topology switching (tx_sched_topo_comp_mode_en), ice_cfg_tx_topo()
> may need to apply a new 5-layer or 9-layer topology from the DDP
> package. If the AQ command to set the topology fails (e.g. due to
> invalid DDP data or firmware limitations), the global configuration
> lock must still be cleared via a CORER reset.
> 
> Commit 86aae43f21cf ("ice: don't leave device non-functional if Tx
> scheduler config fails") correctly fixed this by refactoring
> ice_cfg_tx_topo() to always trigger CORER after acquiring the global
> lock and re-initialize hardware via ice_init_hw() afterwards.
> 
> However, commit 8a37f9e2ff40 ("ice: move ice_deinit_dev() to the end
> of deinit paths") later moved ice_init_dev_hw() into ice_init_hw(),
> breaking the reinit path introduced by 86aae43f21cf. This creates an
> infinite recursive call chain:
> 
>   ice_init_hw()
>     ice_init_dev_hw()
>       ice_cfg_tx_topo()         # topology change needed
>         ice_deinit_hw()
>         ice_init_hw()           # reinit after CORER
>           ice_init_dev_hw()     # recurse
>             ice_cfg_tx_topo()
>               ...               # stack overflow
> 

Oof, ya thats not good. I guess this only happens if the topology needs
to change, so it wouldn't affect many systems where we had already
changed the topology before hand on the old driver.

> Fix by moving ice_init_dev_hw() back out of ice_init_hw() and calling
> it explicitly from ice_probe() and ice_devlink_reinit_up(). The third
> caller, ice_cfg_tx_topo(), intentionally does not need ice_init_dev_hw()
> during its reinit, it only needs the core HW reinitialization. This
> breaks the recursion cleanly without adding flags or guards.
> 
> The deinit ordering changes from commit 8a37f9e2ff40 ("ice: move
> ice_deinit_dev() to the end of deinit paths") which fixed slow rmmod
> are preserved, only the init-side placement of ice_init_dev_hw() is
> reverted.
> 
> Fixes: 8a37f9e2ff40 ("ice: move ice_deinit_dev() to the end of deinit paths")
> Signed-off-by: Petr Oros <poros@redhat.com>

The fix looks correct to me, and definitely the most elegant.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>