From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CD4DC433E1 for ; Thu, 20 Aug 2020 20:16:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2577207DE for ; Thu, 20 Aug 2020 20:16:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jbcRaG2e" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728364AbgHTUQE (ORCPT ); Thu, 20 Aug 2020 16:16:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726908AbgHTUQC (ORCPT ); Thu, 20 Aug 2020 16:16:02 -0400 Received: from mail-yb1-xb43.google.com (mail-yb1-xb43.google.com [IPv6:2607:f8b0:4864:20::b43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB9EDC061385 for ; Thu, 20 Aug 2020 13:16:01 -0700 (PDT) Received: by mail-yb1-xb43.google.com with SMTP id i10so1778717ybt.11 for ; Thu, 20 Aug 2020 13:16:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yL2PYMEwaF7KSjU1XIgM44wQFZt3o+R4J3v1ubBs3g0=; b=jbcRaG2eyfybJbbAPebGLhdbjUShJdWzMVWi5ON7j+zzPYXSqYOMtpq+f2IG7apfik pWHDmawkv4e9vuOVSTcX7RWQ3Yvi3AzxTNrjywSolQPBit+HZdZtFiyUT83VXLgY3/SO CUp49gRYPUlnUvvnMsLLdY97+fegnIELlvNqdpXCZ7Ej9Z/cSa18Zed8QjM+oFx4gi3a COYwYzZe0o3wEFmkV7G0y2mlE8idE/X50HL2dHLMCHbHZ02ZmyQKRj77ISbNqhwCUWwJ vtg1kVFouqjxn28zzXPzpK36f9e0ejF3gHeUrf+yUwl6Ultla7j599+6Jj9MpvFuxORb YOWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yL2PYMEwaF7KSjU1XIgM44wQFZt3o+R4J3v1ubBs3g0=; b=nROZYWPLEfclE4SzpZEv3I1oz54yRqZ1Iat//ZRXkFiu6OAg3S9Flcsybp2s02uJ8w kp4SD/TmrJ/p2TqoaphSqGbeHPruhjKwQ4SagOBeXcR0yBXhRQAF9LpMbcYqMr5N61eC qMDtnddDWF341Hg0yj6LFWfm3nM/kBcfTbxMhV/YDtIluIYeX0ieUGyahSXwlbEPAVYs Nnp7X1zTzxkEbQg/3m3YF/LZ0aq+qOEt94Ndou5lL7E52MDSItGNvDW/aHdGkdcmEeNo kkEajS2E+VzNrH7JE/bXwPPuxIQUgoj2rF9uE4hbQmQc49x0LTs9eOGbOTyLJoc+R1yM iQ6w== X-Gm-Message-State: AOAM53037a5uA1NWYyluyPc1BXO7n3dQXcDVjiSB2SvKyKyFGp79P+gr Ft8IklqtgHGEskLVweTPhozXUw5Oh+Ui2T/MpOA= X-Google-Smtp-Source: ABdhPJxwxU6lRLnz5ToNxC+8qpynxuMGy83QpAyV50kWNa/P95KO/tbTgy5efYGUDIaUDhfOV7gC9+JGl3nV91A4Ees= X-Received: by 2002:a5b:d12:: with SMTP id y18mr6975663ybp.400.1597954561114; Thu, 20 Aug 2020 13:16:01 -0700 (PDT) MIME-Version: 1.0 References: <20200214035555.24762-1-wgong@codeaurora.org> <878se9iup3.fsf@codeaurora.org> <47c1b1e0-afc4-b9b4-5fc0-4636d8b3b981@candelatech.com> In-Reply-To: From: Krishna Chaitanya Date: Fri, 21 Aug 2020 01:45:49 +0530 Message-ID: Subject: Re: [RFC] ath10k: change to do napi_enable and napi_disable when insmod and rmmod for sdio To: Ben Greear Cc: Wen Gong , Kalle Valo , linux-wireless , ath10k Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Thu, Aug 20, 2020 at 11:23 PM Ben Greear wrote: > > On 8/20/20 10:42 AM, Krishna Chaitanya wrote: > > On Thu, Aug 20, 2020 at 11:11 PM Krishna Chaitanya > > wrote: > >> > >> On Thu, Aug 20, 2020 at 10:38 PM Ben Greear wrote: > >>> > >>> On 8/20/20 10:00 AM, Krishna Chaitanya wrote: > >>>> On Thu, Aug 20, 2020 at 10:02 PM Ben Greear wrote: > >>>>> > >>>>> 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. > >>>> 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? > > No, one comment from Michal indicated maybe there were more problems lurking > in this area, but he seemed to be OK with the patch over all. After that, > it was just ignored. > Now might be a good time to push for it :) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-yb1-xb44.google.com ([2607:f8b0:4864:20::b44]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8qyg-0007ZT-VP for ath10k@lists.infradead.org; Thu, 20 Aug 2020 20:16:03 +0000 Received: by mail-yb1-xb44.google.com with SMTP id g3so1801130ybc.3 for ; Thu, 20 Aug 2020 13:16:02 -0700 (PDT) MIME-Version: 1.0 References: <20200214035555.24762-1-wgong@codeaurora.org> <878se9iup3.fsf@codeaurora.org> <47c1b1e0-afc4-b9b4-5fc0-4636d8b3b981@candelatech.com> In-Reply-To: From: Krishna Chaitanya Date: Fri, 21 Aug 2020 01:45:49 +0530 Message-ID: Subject: Re: [RFC] ath10k: change to do napi_enable and napi_disable when insmod and rmmod for sdio List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Ben Greear Cc: linux-wireless , ath10k , Kalle Valo , Wen Gong On Thu, Aug 20, 2020 at 11:23 PM Ben Greear wrote: > > On 8/20/20 10:42 AM, Krishna Chaitanya wrote: > > On Thu, Aug 20, 2020 at 11:11 PM Krishna Chaitanya > > wrote: > >> > >> On Thu, Aug 20, 2020 at 10:38 PM Ben Greear wrote: > >>> > >>> On 8/20/20 10:00 AM, Krishna Chaitanya wrote: > >>>> On Thu, Aug 20, 2020 at 10:02 PM Ben Greear wrote: > >>>>> > >>>>> 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. > >>>> 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? > > No, one comment from Michal indicated maybe there were more problems lurking > in this area, but he seemed to be OK with the patch over all. After that, > it was just ignored. > Now might be a good time to push for it :) _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k