Re: [Intel-wired-lan] [PATCH iwl v3] ice: acquire NVM lock around each flash read

> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of Robert Malz via Intel-wired-lan
> Sent: Friday, July 31, 2026 1:10 PM
> To: Nguyen, Anthony L <[email protected]>; Kitszel,
> Przemyslaw <[email protected]>; Andrew Lunn
> <[email protected]>; David S. Miller <[email protected]>; Eric
> Dumazet <[email protected]>; Jakub Kicinski <[email protected]>; Paolo
> Abeni <[email protected]>; Lobakin, Aleksander
> <[email protected]>; Jesse Brandeburg
> <[email protected]>; Keller, Jacob E <[email protected]>
> Cc: Robert Malz <[email protected]>; intel-wired-
> [email protected]; [email protected]; linux-
> [email protected]
> Subject: [Intel-wired-lan] [PATCH iwl v3] ice: acquire NVM lock around
> each flash read
>=20
> FW caps the NVM read lock at a maximum of 3000ms regardless of the
> timeout requested via ice_acquire_nvm(). ice_read_flat_nvm() splits a
> read into multiple ice_aq_read_nvm() commands, one per 4KB sector, all
> issued under a single lock taken by the caller. Reading a large region
> can exceed 3000ms, so FW reclaims the lock mid-read and the remaining
> commands might fail.
>=20
> Move the lock acquire/release into ice_read_flat_nvm() so it brackets
> each individual ice_aq_read_nvm() command, ensuring the lock is never
> held across more than one FW read.
>=20
> ice_release_nvm() issues its own AQ command and overwrites
> hw->adminq.sq_last_status, which some callers inspect after a failed
> read.
> Add an optional read_aq_err output parameter to ice_read_flat_nvm() to
> capture the failing read's AQ error before the release; callers that
> need it (ice_discover_flash_size() and the ethtool/devlink log paths)
> use it instead of sq_last_status, others pass NULL.
>=20
> Callers that previously took the lock around ice_read_flat_nvm(),
> ice_read_sr_word() or ice_read_flash_module() now call them without
> it.
> The now-redundant per-block locking in ice_devlink_nvm_snapshot() is
> dropped.
>=20
> Fixes: e94509906d6b ("ice: create function to read a section of the
> NVM and Shadow RAM")
> Signed-off-by: Robert Malz <[email protected]>
> ---
> v3:
> - Log the failure via ice_debug() when ice_acquire_nvm() fails inside
>   ice_read_flat_nvm(), rather than silently aborting the read.
> v2:
> - Replace the save/restore of sq_last_status across ice_release_nvm(),
>   which could race with a concurrent AdminQ command, with a new
> optional
>   read_aq_err output parameter.
> - Add missing "Return:" kdoc to ice_read_sr_word().
> ---
>  .../net/ethernet/intel/ice/devlink/devlink.c  | 32 ++------
> drivers/net/ethernet/intel/ice/ice_ethtool.c  | 16 +---
>  drivers/net/ethernet/intel/ice/ice_nvm.c      | 79 +++++++++++-------
> -
>  drivers/net/ethernet/intel/ice/ice_nvm.h      |  2 +-
>  4 files changed, 59 insertions(+), 70 deletions(-)
>=20
> diff --git a/drivers/net/ethernet/intel/ice/devlink/devlink.c
> b/drivers/net/ethernet/intel/ice/devlink/devlink.c
> index 22b7d8e6bd9e..5a1ab9654fb8 100644
> --- a/drivers/net/ethernet/intel/ice/devlink/devlink.c
> +++ b/drivers/net/ethernet/intel/ice/devlink/devlink.c
> @@ -1856,6 +1856,7 @@ static int ice_devlink_nvm_snapshot(struct
> devlink *devlink,  {
>  	struct ice_pf *pf =3D devlink_priv(devlink);
>  	struct device *dev =3D ice_pf_to_dev(pf);

...

>  int
>  ice_get_pfa_module_tlv(struct ice_hw *hw, u16 *module_tlv, u16
> *module_tlv_len,
>  		       u16 module_type);
> --
> 2.34.1


Reviewed-by: Aleksandr Loktionov <[email protected]>