Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751941AbbEDGDv (ORCPT ); Mon, 4 May 2015 02:03:51 -0400 Received: from hofr.at ([212.69.189.236]:36978 "EHLO mail.hofr.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751355AbbEDGDr (ORCPT ); Mon, 4 May 2015 02:03:47 -0400 Date: Mon, 4 May 2015 08:03:46 +0200 From: Nicholas Mc Guire To: Vinod Koul Cc: Laurent Pinchart , Nicholas Mc Guire , Kuninori Morimoto , David Woodhouse , Brian Norris , Wolfram Sang , Arnd Bergmann , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] mtd: sh_flctl: drop unused variable Message-ID: <20150504060346.GB26350@opentech.at> References: <1430553430-21396-1-git-send-email-hofrat@osadl.org> <1430553430-21396-2-git-send-email-hofrat@osadl.org> <1477205.SvYxjlTIEF@avalon> <20150504051723.GW3521@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150504051723.GW3521@localhost> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1874 Lines: 42 On Mon, 04 May 2015, Vinod Koul wrote: > On Sun, May 03, 2015 at 10:33:43PM +0300, Laurent Pinchart wrote: > > Hi Nicholas, > > > > Thank you for the patch. > > > > On Saturday 02 May 2015 09:57:08 Nicholas Mc Guire wrote: > > > shdma_tx_submit() called via dmaengine_submit() returns the assigned > > > cookie but this is not used here so the variable and assignment can > > > be dropped. > > > > > > Signed-off-by: Nicholas Mc Guire > > > > I would rephrase the commit message to avoid mentioning shdma_tx_submit() as > > that's not relevant. Something like "dmaengine_submit() returns the assigned > > cookie but this is not used here so the variable and assignment can be > > dropped." > And I am bit surrised about taht. Ideally the driver should use the cookie > to check the status later on... > looking at other drivers it seems like the drivers should call dma_submit_error(cookie); on the received cookie - which does: return cookie < 0 ? cookie : 0; but doing that after dmaengine_submit() which actually already queued the this request in shdma_base.cc:shdma_tx_submit() might not be that helpful and looking at dma_cookie_assign() I do not see how the condition that dma_submit_error is checking for ever could occur as it can't go below cookie = DMA_MIN_COOKIE which is defined to 1 (include/linux/dmaengine.h) As other drivers seem to not be doing more with the returned cookie than calling dma_submit_error() on it this seems ok here ...but I'm not that deep into this - my starting point was a simple API inconsisteny in the use of wait_for_completion_timeout() :) thx! hofrat -- 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/