> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-boun...@osuosl.org> On Behalf Of Dawid
> Osuchowski
> Sent: Friday, June 7, 2024 5:46 PM
> To: intel-wired-...@lists.osuosl.org
> Cc: Kwan, Ngai-mint <ngai-mint.k...@intel.com>; net...@vger.kernel.org;
> Chmielewski, Pawel <pawel.chmielew...@intel.com>; Simon Horman
> <ho...@kernel.org>; Polchlopek, Mateusz <mateusz.polchlo...@intel.com>; Dawid
> Osuchowski <dawid.osuchow...@linux.intel.com>
> Subject: [Intel-wired-lan] [PATCH iwl-net v5] ice: Do not get coalesce
> settings while in reset
>
> From: Ngai-Mint Kwan <ngai-mint.k...@intel.com>
>
> Getting coalesce settings while reset is in progress can cause NULL pointer
> deference bug.
> If under reset, abort get coalesce for ethtool.
>
> We cannot use ice_wait_for_reset() since both the ethtool handler and the
> adapter reset flow call rtnl_lock() during operation. If we wait for reset
> completion inside of an ethtool handling function such as ice_get_coalesce(),
> the wait will always timeout due to reset being blocked by rtnl_lock() inside
> of ice_queue_set_napi() (which is called during reset process), and in turn
> we will always return -EBUSY anyways, with the added hang time of the timeout
> value.
>
> Fixes: 67fe64d78c43 ("ice: Implement getting and setting ethtool coalesce")
> Signed-off-by: Ngai-Mint Kwan <ngai-mint.k...@intel.com>
> Reviewed-by: Mateusz Polchlopek <mateusz.polchlo...@intel.com>
> Signed-off-by: Pawel Chmielewski <pawel.chmielew...@intel.com>
> Reviewed-by: Simon Horman <ho...@kernel.org>
> Signed-off-by: Dawid Osuchowski <dawid.osuchow...@linux.intel.com>
> ---
> Changes since v1:
> * Added "Fixes:" tag
> Changes since v2:
> * Rebased over current IWL net branch
> * Confirmed that the issue previously reported for this patch [1] by
> Himasekhar Reddy Pucha was caused by other, internally tracked issue Changes
> since v3:
> * Using ice_wait_for_reset() instead of returning -EBUSY Changes since v4:
> * Rebased over current IWL net branch
> * Rollback the use of ice_wait_for_reset() due to rtnl_lock() deadlock issue
> described in [2] and commit msg
>
> [1]
> https://lore.kernel.org/netdev/bl0pr11mb3122d70abde6c2acee376073bd...@bl0pr11mb3122.namprd11.prod.outlook.com/
> [2]
> https://lore.kernel.org/netdev/20240501195641.1e606...@kernel.org/T/#m1629ecfe88d26551852c5c97982cd10314991422
> ---
> drivers/net/ethernet/intel/ice/ice_ethtool.c | 3 +++
> 1 file changed, 3 insertions(+)
>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pu...@intel.com> (A
Contingent worker at Intel)
