On Thu, Aug 20, 2020 at 11:11 PM Krishna Chaitanya <chaitanya.mgit@xxxxxxxxx> wrote: > > On Thu, Aug 20, 2020 at 10:38 PM Ben Greear <greearb@xxxxxxxxxxxxxxx> wrote: > > > > On 8/20/20 10:00 AM, Krishna Chaitanya wrote: > > > On Thu, Aug 20, 2020 at 10:02 PM Ben Greear <greearb@xxxxxxxxxxxxxxx> wrote: > > >> > > >> On 8/20/20 9:08 AM, Krishna Chaitanya wrote: > > >>> On Thu, Aug 20, 2020 at 8:07 PM Wen Gong <wgong@xxxxxxxxxxxxxx> wrote: > > >>>> > > >>>> On 2020-08-20 18:52, Krishna Chaitanya wrote: > > >>>>> On Thu, Aug 20, 2020 at 3:45 PM Wen Gong <wgong@xxxxxxxxxxxxxx> wrote: > > >>>>>> > > >>>>>> On 2020-08-20 17:19, Krishna Chaitanya wrote: > > >>>> ... > > >>>>>>>> I'm not really convinced that this is the right fix, but I'm no NAPI > > >>>>>>>> expert. Can anyone else help? > > >>>>>>> Calling napi_disable() twice can lead to hangs, but moving NAPI from > > >>>>>>> start/stop to > > >>>>>>> the probe isn't the right approach as the datapath is tied to > > >>>>>>> start/stop. > > >>>>>>> > > >>>>>>> Maybe check the state of NAPI before disable? > > >>>>>>> > > >>>>>>> if (test_bit(NAPI_STATE_SCHED, &ar->napi.napi.state)) > > >>>>>>> napi_disable(&ar->napi) > > >>>>>>> or maintain napi_state like this > > >>>>>>> https://patchwork.kernel.org/patch/10249365/ > > >>>>>> it is better to use above link's patch. > > >>>>>> napi.state is controlled by napi API, it is better ath10k not know it. > > >>>>> Sure, but IMHO just canceling the async rx work should solve the issue. > > >>>> Oh no, canceling the async rx work will not solve this issue, rx worker > > >>>> ath10k_rx_indication_async_work call napi_schedule, after napi_complete, > > >>>> the NAPI_STATE_SCHED will clear. > > >>>> The issue of this patch is because 2 thread called to hif_stop and > > >>>> NAPI_STATE_SCHED not clear. > > >>> That fix is still valid and good to have. > > >>> > > >>> ndev_stop being called twice is typical scenarios (stop vs rmmod), so > > >>> just checking the netdev_flags for IFF_UP and returning from hif_Stop > > >>> should suffice, no? > > >> > > >> My approach to fix this problem was to add a boolean in ath10k as to whether > > >> it had napi enabled or not, and then check that before trying to enable/disable > > >> it again. Seems to work fine, and cleaner in my mind than checking internal > > >> napi flags. > > > A much simpler approach is just to check for IFF_UP and skip NAPI (and others) > > > in the hif_stop no? (provided proper RTNL locking is done if hif_stop > > > is being called > > > internally as well). > > > > > > > I'm not sure, but I think the driver should be internally consistent and not > > spend a lot of time trying to guess about interactions with objects higher > > in the stack. > Fair enough, the network interface state is a basic thing controlled > by the driver, > so, should be okay to use. Anyways, the in-driver approach has more control. > > > > Here is my original patch to fix this, it is not complex. > > > > https://patchwork.kernel.org/patch/10249363/ > Sure, I have shared your patch above :). Sent a bit early, any idea why this wasn't upstreamed earlier?
