On Fri, 1 Nov 2024 02:34:59 +0900 Taehee Yoo wrote: > While I'm writing a patch I face an ambiguous problem here. > ethnl_set_ring() first calls .get_ringparam() to get current config. > Then it calls .set_ringparam() after it sets the current config + new > config to param structures. > The bnxt_set_ringparam() may receive ETHTOOL_TCP_DATA_SPLIT_ENABLED > because two cases. > 1. from user > 2. from bnxt_get_ringparam() because of UNKNWON. > The problem is that the bnxt_set_ringparam() can't distinguish them. > The problem scenario is here. > 1. tcp-data-split is UNKNOWN mode. > 2. HDS is automatically enabled because one of LRO or GRO is enabled. > 3. user changes ring parameter with following command > `ethtool -G eth0 rx 1024` > 4. ethnl_set_rings() calls .get_ringparam() to get current config. > 5. bnxt_get_ringparam() returns ENABLE of HDS because of UNKNWON mode. > 6. ethnl_set_rings() calls .set_ringparam() after setting param with > configs comes from .get_ringparam(). > 7. bnxt_set_ringparam() is passed ETHTOOL_TCP_DATA_SPLIT_ENABLED but > the user didn't set it explicitly. > 8. bnxt_set_ringparam() eventually force enables tcp-data-split. > > I couldn't find a way to distinguish them so far. > I'm not sure if this is acceptable or not. > Maybe we need to modify a scenario? I thought we discussed this, but I may be misremembering. You may need to record in the core whether the setting came from the user or not (similarly to IFF_RXFH_CONFIGURED). User setting UNKNWON would mean "reset". Maybe I'm misunderstanding..
