Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751522AbbBKCK2 (ORCPT ); Tue, 10 Feb 2015 21:10:28 -0500 Received: from mail-vc0-f171.google.com ([209.85.220.171]:46917 "EHLO mail-vc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823AbbBKCK0 (ORCPT ); Tue, 10 Feb 2015 21:10:26 -0500 MIME-Version: 1.0 In-Reply-To: <1421758677-183443-1-git-send-email-heikki.krogerus@linux.intel.com> References: <1421758677-183443-1-git-send-email-heikki.krogerus@linux.intel.com> Date: Wed, 11 Feb 2015 10:10:25 +0800 X-Google-Sender-Auth: NNOkVwkYx4qnAT7glbchf0NFK4g Message-ID: Subject: Re: [PATCH] dmaengine: dw: support for clockless platforms From: Viresh Kumar To: Heikki Krogerus , Russell King Cc: Andy Shevchenko , Vinod Koul , "linux-kernel@vger.kernel.org" , dmaengine@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1514 Lines: 37 On Tue, Jan 20, 2015 at 8:57 PM, Heikki Krogerus wrote: > When requesting clock in the platform driver, leaving > chip->clk value as NULL if -ENOENT is returned, and > continue. With other errors returning failure. It makes the > driver usable on platforms that do not provide the clock. > > Signed-off-by: Heikki Krogerus > --- > drivers/dma/dw/platform.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c > index 32ea1ac..b183bc0 100644 > --- a/drivers/dma/dw/platform.c > +++ b/drivers/dma/dw/platform.c > @@ -180,8 +180,12 @@ static int dw_probe(struct platform_device *pdev) > chip->dev = dev; > > chip->clk = devm_clk_get(chip->dev, "hclk"); > - if (IS_ERR(chip->clk)) > - return PTR_ERR(chip->clk); > + if (IS_ERR(chip->clk)) { > + if (PTR_ERR(chip->clk) == -ENOENT) > + chip->clk = NULL; This is wrong and reasons are mentioned in this thread: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-March/088437.html You don't need to set it to NULL, if CONFIG_HAVE_CLK isn't set the dummy routines would take care of it. -- 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/