Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753472AbbLWFpe (ORCPT ); Wed, 23 Dec 2015 00:45:34 -0500 Received: from mail-ig0-f176.google.com ([209.85.213.176]:37939 "EHLO mail-ig0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752014AbbLWFpc (ORCPT ); Wed, 23 Dec 2015 00:45:32 -0500 MIME-Version: 1.0 In-Reply-To: <1450841723-6227-1-git-send-email-ashutosh.dixit@intel.com> References: <1450841723-6227-1-git-send-email-ashutosh.dixit@intel.com> Date: Wed, 23 Dec 2015 11:15:31 +0530 Message-ID: Subject: Re: [PATCH] dma: Revert "dmaengine: mic_x100: add missing spin_unlock" From: Saurabh Sengar To: Ashutosh Dixit Cc: Vinod Koul , linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Sudeep Dutt , Nikhil Rao , Siva Yerramreddy Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2757 Lines: 80 On 23 December 2015 at 09:05, Ashutosh Dixit wrote: > This reverts commit e958e079e254 ("dmaengine: mic_x100: add missing > spin_unlock"). > > The above patch is incorrect. There is nothing wrong with the original > code. The spin_lock is acquired in the "prep" functions and released > in "submit". Hi Ashutosh, If it is need to be released by submit function, we don't require the spin_unlock on success case as well. am I correct ? > Signed-off-by: Ashutosh Dixit > --- > drivers/dma/mic_x100_dma.c | 15 +++++---------- > 1 file changed, 5 insertions(+), 10 deletions(-) > > diff --git a/drivers/dma/mic_x100_dma.c b/drivers/dma/mic_x100_dma.c > index cddfa8d..068e920 100644 > --- a/drivers/dma/mic_x100_dma.c > +++ b/drivers/dma/mic_x100_dma.c > @@ -317,7 +317,6 @@ mic_dma_prep_memcpy_lock(struct dma_chan *ch, dma_addr_t dma_dest, > struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch); > struct device *dev = mic_dma_ch_to_device(mic_ch); > int result; > - struct dma_async_tx_descriptor *tx = NULL; > > if (!len && !flags) > return NULL; > @@ -325,13 +324,10 @@ mic_dma_prep_memcpy_lock(struct dma_chan *ch, dma_addr_t dma_dest, > spin_lock(&mic_ch->prep_lock); > result = mic_dma_do_dma(mic_ch, flags, dma_src, dma_dest, len); > if (result >= 0) > - tx = allocate_tx(mic_ch); > - > - if (!tx) > - dev_err(dev, "Error enqueueing dma, error=%d\n", result); > - > + return allocate_tx(mic_ch); > + dev_err(dev, "Error enqueueing dma, error=%d\n", result); > spin_unlock(&mic_ch->prep_lock); This spin_unlock shouldn't be required as explained it is getting released by submit function > - return tx; > + return NULL; > } > > static struct dma_async_tx_descriptor * > @@ -339,14 +335,13 @@ mic_dma_prep_interrupt_lock(struct dma_chan *ch, unsigned long flags) > { > struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch); > int ret; > - struct dma_async_tx_descriptor *tx = NULL; > > spin_lock(&mic_ch->prep_lock); > ret = mic_dma_do_dma(mic_ch, flags, 0, 0, 0); > if (!ret) > - tx = allocate_tx(mic_ch); > + return allocate_tx(mic_ch); > spin_unlock(&mic_ch->prep_lock); and this too ? > - return tx; > + return NULL; > } > > /* Return the status of the transaction */ > -- > 2.0.0.rc3.2.g998f840 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/