From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965045AbcHDP4S (ORCPT ); Thu, 4 Aug 2016 11:56:18 -0400 Received: from mail-lf0-f49.google.com ([209.85.215.49]:35827 "EHLO mail-lf0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932490AbcHDP4Q (ORCPT ); Thu, 4 Aug 2016 11:56:16 -0400 Subject: Re: [PATCH] net: ethernet: ti: cpdma: remove used_desc counter To: Grygorii Strashko , "David S. Miller" , netdev@vger.kernel.org, Mugunthan V N References: <20160804152051.30565-1-grygorii.strashko@ti.com> Cc: Sekhar Nori , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org From: Ivan Khoronzhuk Message-ID: <614baaea-0b60-647b-6000-d4676a94df6b@linaro.org> Date: Thu, 4 Aug 2016 18:56:12 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20160804152051.30565-1-grygorii.strashko@ti.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04.08.16 18:20, Grygorii Strashko wrote: > The struct cpdma_desc_pool->used_desc field can be safely removed from > CPDMA driver (and hot patch) because used_descs counter is used just > for pool consistency check at CPDMA deinitialization and now this > check can be re-implemnted using gen_pool_size(pool->gen_pool) != > gen_pool_avail(pool->gen_pool). > More over, this will allow to get rid of warnings in > cpdma_desc_pool_destro()-> WARN_ON(pool->used_desc) which may happen > because the used_descs is used unprotected, since CPDMA has been > switched to use genalloc, and may get wrong values on SMP. > > Hence, remove used_desc from struct cpdma_desc_pool. > > Signed-off-by: Grygorii Strashko > --- > drivers/net/ethernet/ti/davinci_cpdma.c | 18 +++++++----------- > 1 file changed, 7 insertions(+), 11 deletions(-) > > diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c > index 19e5f32..cf72b33 100644 > --- a/drivers/net/ethernet/ti/davinci_cpdma.c > +++ b/drivers/net/ethernet/ti/davinci_cpdma.c > @@ -86,7 +86,7 @@ struct cpdma_desc_pool { > void __iomem *iomap; /* ioremap map */ > void *cpumap; /* dma_alloc map */ > int desc_size, mem_size; > - int num_desc, used_desc; > + int num_desc; > struct device *dev; > struct gen_pool *gen_pool; > }; > @@ -148,7 +148,10 @@ static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool) > if (!pool) > return; > > - WARN_ON(pool->used_desc); > + WARN(gen_pool_size(pool->gen_pool) != gen_pool_avail(pool->gen_pool), > + "cpdma_desc_pool size %d != avail %d", > + gen_pool_size(pool->gen_pool), > + gen_pool_avail(pool->gen_pool)); > if (pool->cpumap) > dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap, > pool->phys); > @@ -232,21 +235,14 @@ desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma) > static struct cpdma_desc __iomem * > cpdma_desc_alloc(struct cpdma_desc_pool *pool) > { > - struct cpdma_desc __iomem *desc = NULL; > - > - desc = (struct cpdma_desc __iomem *)gen_pool_alloc(pool->gen_pool, > - pool->desc_size); > - if (desc) > - pool->used_desc++; > - > - return desc; > + return (struct cpdma_desc __iomem *) > + gen_pool_alloc(pool->gen_pool, pool->desc_size); > } > > static void cpdma_desc_free(struct cpdma_desc_pool *pool, > struct cpdma_desc __iomem *desc, int num_desc) > { > gen_pool_free(pool->gen_pool, (unsigned long)desc, pool->desc_size); > - pool->used_desc--; > } > > struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params) > -- Regards, Ivan Khoronzhuk