From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753235AbaCAQd0 (ORCPT ); Sat, 1 Mar 2014 11:33:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43947 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752972AbaCAQdY (ORCPT ); Sat, 1 Mar 2014 11:33:24 -0500 Message-ID: <53120BA8.3000508@redhat.com> Date: Sat, 01 Mar 2014 17:32:40 +0100 From: Hans de Goede User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: linux-sunxi@googlegroups.com, Emilio Lopez , Dan Williams , Vinod Koul CC: Mike Turquette , linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, kevin.z.m.zh@gmail.com, sunny@allwinnertech.com, shuge@allwinnertech.com, zhuzhenhua@allwinnertech.com, Maxime Ripard Subject: Re: [linux-sunxi] [PATCH v2 2/5] clk: sun6i: Reparent AHB clock on PLL6 References: <1393605440-14643-1-git-send-email-maxime.ripard@free-electrons.com> <1393605440-14643-3-git-send-email-maxime.ripard@free-electrons.com> In-Reply-To: <1393605440-14643-3-git-send-email-maxime.ripard@free-electrons.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 02/28/2014 05:37 PM, Maxime Ripard wrote: > In order for the DMA controller to work for SDRAM to devices transfers, the AHB > clock should be reparented on the PLL6. > > Force that parenting in the clock driver. > > Signed-off-by: Maxime Ripard > --- > drivers/clk/sunxi/clk-sunxi.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c > index f6f61cc..a5c5882 100644 > --- a/drivers/clk/sunxi/clk-sunxi.c > +++ b/drivers/clk/sunxi/clk-sunxi.c > @@ -1286,7 +1286,7 @@ static void __init of_sunxi_table_clock_setup(const struct of_device_id *clk_mat > */ > static void __init sunxi_clock_protect(void) > { > - struct clk *clk; > + struct clk *clk, *parent; > > /* memory bus clock - sun5i+ */ > clk = clk_get(NULL, "mbus"); > @@ -1307,6 +1307,22 @@ static void __init sunxi_clock_protect(void) > if (!IS_ERR(clk)) > clk_prepare_enable(clk); > > + clk = clk_get(NULL, "ahb1_mux"); > + if (IS_ERR(clk)) { > + pr_err("Couldn't get AHB1 Mux\n"); > + return; > + } I think Emilio already made a similar remark for v1, but since this is still here in v2, ahb1_mux is only available on sun6i, so at a minimum the pr_err should be dropped. Preferably I would like to see this changed to something like: clk = clk_get(NULL, "ahb1_mux"); parent = clk_get(NULL, "pll6"); if (!IS_ERR(clk) && !IS_ERR(parent)) clk_set_parent(clk, parent); if (!IS_ERR(parent)) clk_put(parent); if (!IS_ERR(clk)) clk_put(clk); > + > + parent = clk_get(NULL, "pll6"); > + if (IS_ERR(clk)) { Copy paste error should be IS_ERR(parent). > + pr_err("Couldn't get PLL6\n"); If we keep things this way this error path should do a clk_put(clk); > + return; > + } > + > + clk_set_parent(clk, parent); > + > + clk_put(clk); > + clk_put(parent); > } > > static void __init sunxi_init_clocks(void) > Regards, Hans p.s. Given Russell's remarks it would also be good to have a patch in this set dropping the clk_put calls of the existing enables / protections.