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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 75B59C12002 for ; Mon, 19 Jul 2021 06:36:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E7F06024A for ; Mon, 19 Jul 2021 06:36:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234345AbhGSGjI (ORCPT ); Mon, 19 Jul 2021 02:39:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233048AbhGSGjH (ORCPT ); Mon, 19 Jul 2021 02:39:07 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AAC2C061762; Sun, 18 Jul 2021 23:36:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=5NrnS2Yq56znVmTxYxB3qTnbwKzTQfFAIeiV2C3dA0w=; t=1626676568; x=1627886168; b=Uw7PILSM8BIf+nGBbASBFPJ5QrZxRBSaFq/gCUmRH5tSo2d j+fhER3QwrjqIsInaQnMAma1z+TTFDJER6ssH+S06c9+rqQ4HCasjDap/seb0Px+YWxFRY9dekzek mw4PiTaE7yzDsDA0sR+D1lLrsvr9L10Z4L4x8TL4q9ba1DXCTynee85fNii5spVwHLpPQllWVOXgi 2blkrcqPx5thFslvbIIDmy/SkvYrjM1LIRUT+e6M4P+BEaTvBtbnUDm66IxeH0Ydeb86e+cIfVS0Y JLgxQ7+PZHgYSkLMSGGjEQXfNszk2Qd3ugY5x0QRwacv7QTux6id+jj9sv1Vu7xw==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1m5Msm-004FwI-Rj; Mon, 19 Jul 2021 08:36:04 +0200 Message-ID: <27d8246ef3c9755b3e6e908188ca36f7b0fab3fc.camel@sipsolutions.net> Subject: Re: [PATCH RFC v1 3/7] rtw88: Use rtw_iterate_stas where the iterator reads or writes registers From: Johannes Berg To: Martin Blumenstingl , linux-wireless@vger.kernel.org Cc: tony0620emma@gmail.com, kvalo@codeaurora.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Neo Jou , Jernej Skrabec Date: Mon, 19 Jul 2021 08:36:04 +0200 In-Reply-To: <20210717204057.67495-4-martin.blumenstingl@googlemail.com> References: <20210717204057.67495-1-martin.blumenstingl@googlemail.com> <20210717204057.67495-4-martin.blumenstingl@googlemail.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-malware-bazaar: not-scanned Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, 2021-07-17 at 22:40 +0200, Martin Blumenstingl wrote: > > --- a/drivers/net/wireless/realtek/rtw88/mac80211.c > +++ b/drivers/net/wireless/realtek/rtw88/mac80211.c > @@ -721,7 +721,7 @@ static void rtw_ra_mask_info_update(struct rtw_dev *rtwdev, >   br_data.rtwdev = rtwdev; >   br_data.vif = vif; >   br_data.mask = mask; > - rtw_iterate_stas_atomic(rtwdev, rtw_ra_mask_info_update_iter, &br_data); > + rtw_iterate_stas(rtwdev, rtw_ra_mask_info_update_iter, &br_data); And then you pretty much immediately break that invariant here, namely that you're calling this within the set_bitrate_mask() method called by mac80211. That's not actually fundamentally broken today, but it does *severely* restrict what we can do in mac80211 wrt. locking, and I really don't want to keep the dozen or so locks forever, this needs simplification because clearly we don't even know what should be under what lock. So like I said on the other patch, I don't have a fundamental objection to taking such a patch, but the locking mess that this gets us into is something I'd rather not have. Maybe just don't support set_bitrate_mask for SDIO drivers for now? The other cases look OK, it's being called from outside contexts (wowlan, etc.) johannes