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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6DC39C43603 for ; Mon, 9 Dec 2019 07:48:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1200A20721 for ; Mon, 9 Dec 2019 07:48:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="ceKFr7xq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727115AbfLIHsh (ORCPT ); Mon, 9 Dec 2019 02:48:37 -0500 Received: from lelv0143.ext.ti.com ([198.47.23.248]:37502 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727110AbfLIHsh (ORCPT ); Mon, 9 Dec 2019 02:48:37 -0500 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id xB97mIlZ125688; Mon, 9 Dec 2019 01:48:18 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1575877698; bh=/0OolTf7xPjmzWMZGfI2SBPCf/vaYYJ1EEPkW2UwwEw=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=ceKFr7xqrZZf89a0ja+RMDPCmpefuOJsNfpPI6mvKKir38ejEaQ+zE7KOEuGywjCx 7V5fPCaokW+EbT23uVWN5N0V24XnOCX6G9O/yZC/cNfkmXZlkpIaZjKt93Wa15y2eE MqLtqYkGw57SUa+y5jJr0bx1cZOaTHwQ8HeU3jFk= Received: from DFLE102.ent.ti.com (dfle102.ent.ti.com [10.64.6.23]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id xB97mIQM127920 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 9 Dec 2019 01:48:18 -0600 Received: from DFLE112.ent.ti.com (10.64.6.33) by DFLE102.ent.ti.com (10.64.6.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Mon, 9 Dec 2019 01:48:16 -0600 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Mon, 9 Dec 2019 01:48:16 -0600 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id xB97mE9d013491; Mon, 9 Dec 2019 01:48:15 -0600 Subject: Re: [PATCH 2/5] dmaengine: virt-dma: Do not call desc_free() under a spin_lock To: Sascha Hauer , CC: Vinod Koul , Pengutronix Kernel Team , NXP Linux Team , Robert Jarzmik References: <20191206135344.29330-1-s.hauer@pengutronix.de> <20191206135344.29330-3-s.hauer@pengutronix.de> From: Peter Ujfalusi Message-ID: <65b923ed-4370-089c-1d6c-ce7efac176e6@ti.com> Date: Mon, 9 Dec 2019 09:48:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191206135344.29330-3-s.hauer@pengutronix.de> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Hi Sascha, On 06/12/2019 15.53, Sascha Hauer wrote: > vchan_vdesc_fini() shouldn't be called under a spin_lock. This is done > in two places, once in vchan_terminate_vdesc() and once in > vchan_synchronize(). Instead of freeing the vdesc right away, collect > the aborted vdescs on a separate list and free them along with the other > vdescs. > > Signed-off-by: Sascha Hauer > --- > drivers/dma/virt-dma.c | 1 + > drivers/dma/virt-dma.h | 17 +++-------------- > 2 files changed, 4 insertions(+), 14 deletions(-) > > diff --git a/drivers/dma/virt-dma.c b/drivers/dma/virt-dma.c > index ec4adf4260a0..87d5bd53c98b 100644 > --- a/drivers/dma/virt-dma.c > +++ b/drivers/dma/virt-dma.c > @@ -135,6 +135,7 @@ void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev) > INIT_LIST_HEAD(&vc->desc_submitted); > INIT_LIST_HEAD(&vc->desc_issued); > INIT_LIST_HEAD(&vc->desc_completed); > + INIT_LIST_HEAD(&vc->desc_aborted); Can we keep the terminated term instead of aborted: desc_terminated > > tasklet_init(&vc->task, vchan_complete, (unsigned long)vc); > > diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h > index 41883ee2c29f..6cae93624f0d 100644 > --- a/drivers/dma/virt-dma.h > +++ b/drivers/dma/virt-dma.h > @@ -31,9 +31,9 @@ struct virt_dma_chan { > struct list_head desc_submitted; > struct list_head desc_issued; > struct list_head desc_completed; > + struct list_head desc_aborted; > > struct virt_dma_desc *cyclic; > - struct virt_dma_desc *vd_terminated; > }; > > static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan) > @@ -146,11 +146,8 @@ static inline void vchan_terminate_vdesc(struct virt_dma_desc *vd) > { > struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan); > > - /* free up stuck descriptor */ > - if (vc->vd_terminated) > - vchan_vdesc_fini(vc->vd_terminated); > + list_add_tail(&vd->node, &vc->desc_aborted); > > - vc->vd_terminated = vd; > if (vc->cyclic == vd) > vc->cyclic = NULL; > } > @@ -184,6 +181,7 @@ static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc, > list_splice_tail_init(&vc->desc_submitted, head); > list_splice_tail_init(&vc->desc_issued, head); > list_splice_tail_init(&vc->desc_completed, head); > + list_splice_tail_init(&vc->desc_aborted, head); > } > > static inline void vchan_free_chan_resources(struct virt_dma_chan *vc) > @@ -212,16 +210,7 @@ static inline void vchan_free_chan_resources(struct virt_dma_chan *vc) > */ > static inline void vchan_synchronize(struct virt_dma_chan *vc) > { > - unsigned long flags; > - > tasklet_kill(&vc->task); > - > - spin_lock_irqsave(&vc->lock, flags); > - if (vc->vd_terminated) { > - vchan_vdesc_fini(vc->vd_terminated); > - vc->vd_terminated = NULL; > - } > - spin_unlock_irqrestore(&vc->lock, flags); We don't want the terminated descriptors to accumulate until the channel is freed up. spin_lock_irqsave(&vc->lock, flags); list_splice_tail_init(&vc->desc_terminated, &head); spin_unlock_irqrestore(&vc->lock, flags); list_for_each_entry_safe(vd, _vd, &head, node) { list_del(&vd->node); vchan_vdesc_fini(vd); } > } > > #endif > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki