From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail2.candelatech.com ([208.74.158.173] helo=mail3.candelatech.com) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8nUk-00010O-TJ for ath10k@lists.infradead.org; Thu, 20 Aug 2020 16:32:55 +0000 Subject: Re: [RFC] ath10k: change to do napi_enable and napi_disable when insmod and rmmod for sdio References: <20200214035555.24762-1-wgong@codeaurora.org> <878se9iup3.fsf@codeaurora.org> From: Ben Greear Message-ID: Date: Thu, 20 Aug 2020 09:32:52 -0700 MIME-Version: 1.0 In-Reply-To: Content-Language: en-MW List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Krishna Chaitanya , Wen Gong Cc: linux-wireless , ath10k , Kalle Valo On 8/20/20 9:08 AM, Krishna Chaitanya wrote: > On Thu, Aug 20, 2020 at 8:07 PM Wen Gong wrote: >> >> On 2020-08-20 18:52, Krishna Chaitanya wrote: >>> On Thu, Aug 20, 2020 at 3:45 PM Wen Gong 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. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k