On Thu, Aug 20, 2020 at 3:45 PM Wen Gong <wgong@xxxxxxxxxxxxxx> wrote: > > On 2020-08-20 17:19, Krishna Chaitanya wrote: > ... > >> > diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c > >> > index 7b894dcaad2e..b71499b171c6 100644 > >> > --- a/drivers/net/wireless/ath/ath10k/sdio.c > >> > +++ b/drivers/net/wireless/ath/ath10k/sdio.c > >> > @@ -1756,8 +1756,6 @@ static int ath10k_sdio_hif_start(struct ath10k *ar) > >> > struct ath10k_sdio *ar_sdio = ath10k_sdio_priv(ar); > >> > int ret; > >> > > >> > - napi_enable(&ar->napi); > >> > - > >> > /* Sleep 20 ms before HIF interrupts are disabled. > >> > * This will give target plenty of time to process the BMI done > >> > * request before interrupts are disabled. > >> > @@ -1884,7 +1882,6 @@ static void ath10k_sdio_hif_stop(struct ath10k *ar) > >> > spin_unlock_bh(&ar_sdio->wr_async_lock); > >> > > >> > napi_synchronize(&ar->napi); > >> > - napi_disable(&ar->napi); > >> > } > >> > > >> > #ifdef CONFIG_PM > >> > @@ -2121,6 +2118,7 @@ static int ath10k_sdio_probe(struct sdio_func *func, > >> > > >> > netif_napi_add(&ar->napi_dev, &ar->napi, ath10k_sdio_napi_poll, > >> > ATH10K_NAPI_BUDGET); > >> > + napi_enable(&ar->napi); > >> > > >> > ath10k_dbg(ar, ATH10K_DBG_BOOT, > >> > "sdio new func %d vendor 0x%x device 0x%x block 0x%x/0x%x\n", > >> > @@ -2235,6 +2233,7 @@ static void ath10k_sdio_remove(struct sdio_func *func) > >> > > >> > ath10k_core_unregister(ar); > >> > > >> > + napi_disable(&ar->napi); > >> > netif_napi_del(&ar->napi); > >> > > >> > ath10k_core_destroy(ar); > >> > >> 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. > > Also, the most common cause for such issues (1st > > napi_synchronize/napi_disable hang) > > is that napi_poll is being scheduled, so, you might want to check that > > napi_schedule isn't > > called after stop. > > > > cd ath10k; git log --grep=napi shows plenty of such issues. the one > > that matches closest is > > c2cac2f74ab4bcf0db0dcf3a612f1e5b52d145c8, so, it could just be a > > regression. > This above commit's scene is not same with this patch. > It is hang for only do 1 simulate crash of the commit, this patch is > doing simulate crash and rmmod meanwhile. yes, it is the closest one I could find.
