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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 42F49C35FFC for ; Tue, 17 Sep 2024 09:21:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:CC:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1JHCD/69VTCYscf7qteQl5ACCgoQ/36oUJ28AIZ9YE4=; b=NcfIosHDUVw2iocYEO/LtlozHz s2+8380O7SeJlaQX1FtQVnLPhcQD0qjxgTjjYuTkKXBiqqSkNbv/0G1lERxXuq28/lC0y4hLwkPGc DQ3xhUX1LZixlNR5fCRjrzKuMyzmqMaqqoFsAfesZL1GUyXr2gnLjmzcEo+y7Z3W4KS/4gDfUNspa wHFntKwZi25aLZYAw5qzbopa8Us/DfZOfJZWDIAYb4sMfvMKDvPB14wEniiBHt1BSMmJO4RrBjRUE EcQb3MhtnpRrrm5ig9mC+UjyucL9JX86PrKb2dMbK3GoHiTVLH+8bVb4Qsc81HffdtssWGseHytbI rgmig4vw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1sqUOR-00000005oXr-4A0X; Tue, 17 Sep 2024 09:21:07 +0000 Received: from lelv0143.ext.ti.com ([198.47.23.248]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1sqUN9-00000005oO7-3BvY for linux-arm-kernel@lists.infradead.org; Tue, 17 Sep 2024 09:20:00 +0000 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 48H9Jhv0088904; Tue, 17 Sep 2024 04:19:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1726564783; bh=1JHCD/69VTCYscf7qteQl5ACCgoQ/36oUJ28AIZ9YE4=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=CBLrMnu9rFcHI/W0hnPX4uuCniRT9HvTQzGOZKs5IyLIYzIMwPVquSS6oWbEqCdXe Ji5jfyo0NGf/wBBlyQ9BskPp4o03Heaq5i+XO8IDtQEXwR2fXgY6dbG91eFYR3BGfQ PUV91bUrpeFV+r55OKjh/eW/y4fj6W/5oN7iHru0= Received: from DFLE105.ent.ti.com (dfle105.ent.ti.com [10.64.6.26]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTP id 48H9Jh5p019052; Tue, 17 Sep 2024 04:19:43 -0500 Received: from DFLE113.ent.ti.com (10.64.6.34) by DFLE105.ent.ti.com (10.64.6.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 17 Sep 2024 04:19:43 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DFLE113.ent.ti.com (10.64.6.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Tue, 17 Sep 2024 04:19:43 -0500 Received: from [172.24.19.92] (lt5cd2489kgj.dhcp.ti.com [172.24.19.92]) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 48H9JdDr035699; Tue, 17 Sep 2024 04:19:40 -0500 Message-ID: <5e52e8f4-cb50-4490-a9ce-c9074b3d9b7a@ti.com> Date: Tue, 17 Sep 2024 14:49:39 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH] remoteproc: k3-r5: Fix check performed in k3_r5_rproc_{mbox_callback/kick} To: Mathieu Poirier CC: Siddharth Vadapalli , Hari Nagalla , Andrew Davis , , , , , , , References: <20240916083131.2801755-1-s-vadapalli@ti.com> <3ca4b2d1-5c47-4f85-969d-cd61c7ade2dc@ti.com> Content-Language: en-US From: "Kumar, Udit" In-Reply-To: <3ca4b2d1-5c47-4f85-969d-cd61c7ade2dc@ti.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240917_021947_870066_432744B5 X-CRM114-Status: GOOD ( 27.76 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 9/17/2024 2:43 PM, Kumar, Udit wrote: > Hi Mathieu, > > On 9/17/2024 2:07 PM, Mathieu Poirier wrote: >> On Mon, 16 Sept 2024 at 23:20, Kumar, Udit wrote: >>> On 9/16/2024 8:50 PM, Mathieu Poirier wrote: >>>> On Mon, 16 Sept 2024 at 02:31, Siddharth Vadapalli >>>> wrote: >>>>> Commit f3f11cfe8907 ("remoteproc: k3-r5: Acquire mailbox handle >>>>> during >>>>> probe routine") introduced a check in the >>>>> "k3_r5_rproc_mbox_callback()" and >>>>> "k3_r5_rproc_kick()" callbacks, causing them to exit if the remote >>>>> core's >>>>> state is "RPROC_DETACHED". However, the "__rproc_attach()" >>>>> function that is >>>>> responsible for attaching to a remote core, updates the state of >>>>> the remote >>>>> core to "RPROC_ATTACHED" only after invoking >>>>> "rproc_start_subdevices()". >>>>> >>>>> The "rproc_start_subdevices()" function triggers the probe of the >>>>> Virtio >>>>> RPMsg devices associated with the remote core, which require that the >>>>> "k3_r5_rproc_kick()" and "k3_r5_rproc_mbox_callback()" callbacks are >>>>> functional. Hence, drop the check in the callbacks. >>>> Honestly, I am very tempted to just revert f3f11cfe8907 and >>>> ea1d6fb5b571. >>> >>> Please don't :) , it will break rproc in general for k3 devices. >>> >> Why not - it is already broken anyway.  Reverting the patches will >> force TI to actually think about the feature in terms of design, >> completeness and testing.  The merge window opened on Sunday - I'm not >> going to merge whack-a-mole patches and hope the right fix comes >> along. > > Now, I am not advocating here to revert or not. > > But where we stand currently > > 1-  Without this patch, IPC is broken in general. > > 2-  With this patch, IPC is conditionally broken. Sorry for confusion, here _this_ patch I meant below commit ids f3f11cfe8907 and ea1d6fb5b571. > > In either case, we need to fix it. > > your call to revert or keep it. > > >> >>> Couple of solutions for this race around condition (in mine preference >>> order) >>> >> This is for the TI team to discuss _and_ test thoroughly.  From hereon >> and until I see things improve, all patches from TI will need to be >> tagged with R-B and T-B tags (collected on the mailing lists) from two >> different individuals before I look at them. > > Sure we will take care of above > > and fair ask on R-B and T-B tags > >> >>> 1) In >>> https://elixir.bootlin.com/linux/v6.11/source/drivers/remoteproc/ti_k3_r5_remoteproc.c#L190 >>> >>> have a check , if probe in is progress or not >>> >>> 2) >>> https://elixir.bootlin.com/linux/v6.11/source/drivers/remoteproc/ti_k3_r5_remoteproc.c#L1205 >>> >>> -- correct the state to ON or something else >>> >>> 3) Move condition >>> https://elixir.bootlin.com/linux/v6.11/source/drivers/remoteproc/remoteproc_core.c#L1360 >>> >>> before rproc_start_subdevices >>> >>> calling >>> >>> >>> >>>>> Fixes: f3f11cfe8907 ("remoteproc: k3-r5: Acquire mailbox handle >>>>> during probe routine") >>>>> Signed-off-by: Siddharth Vadapalli >>>>> --- >>>>> >>>>> Hello, >>>>> >>>>> Since the commit being fixed is not yet a part of Mainline Linux, >>>>> this >>>>> patch is based on linux-next tagged next-20240913. >>>>> >>>>> An alternative to this patch will be a change to the >>>>> "__rproc_attach()" >>>>> function in the "remoteproc_core.c" driver with >>>>> rproc->state = RPROC_ATTACHED; >>>>> being set after "rproc_attach_device()" is invoked, but __before__ >>>>> invoking "rproc_start_subdevices()". Since this change will be >>>>> performed >>>>> in the common Remoteproc Core, it appeared to me that fixing it in >>>>> the >>>>> TI remoteproc driver is the correct approach. >>>>> >>>>> The equivalent of this patch for ti_k3_dsp_remoteproc.c might also be >>>>> required, which I shall post if the current patch is acceptable. >>>>> >>>>> Kindly review and share your feedback on this patch. >>>>> >>>>> Regards, >>>>> Siddharth. >>>>> >>>>>    drivers/remoteproc/ti_k3_r5_remoteproc.c | 8 -------- >>>>>    1 file changed, 8 deletions(-) >>>>> >>>>> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c >>>>> b/drivers/remoteproc/ti_k3_r5_remoteproc.c >>>>> index 747ee467da88..4894461aa65f 100644 >>>>> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c >>>>> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c >>>>> @@ -194,10 +194,6 @@ static void k3_r5_rproc_mbox_callback(struct >>>>> mbox_client *client, void *data) >>>>>           const char *name = kproc->rproc->name; >>>>>           u32 msg = omap_mbox_message(data); >>>>> >>>>> -       /* Do not forward message from a detached core */ >>>>> -       if (kproc->rproc->state == RPROC_DETACHED) >>>>> -               return; >>>>> - >>>>>           dev_dbg(dev, "mbox msg: 0x%x\n", msg); >>>>> >>>>>           switch (msg) { >>>>> @@ -233,10 +229,6 @@ static void k3_r5_rproc_kick(struct rproc >>>>> *rproc, int vqid) >>>>>           mbox_msg_t msg = (mbox_msg_t)vqid; >>>>>           int ret; >>>>> >>>>> -       /* Do not forward message to a detached core */ >>>>> -       if (kproc->rproc->state == RPROC_DETACHED) >>>>> -               return; >>>>> - >>>>>           /* send the index of the triggered virtqueue in the >>>>> mailbox payload */ >>>>>           ret = mbox_send_message(kproc->mbox, (void *)msg); >>>>>           if (ret < 0) >>>>> -- >>>>> 2.40.1 >>>>>