Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752548AbcLFMUp (ORCPT ); Tue, 6 Dec 2016 07:20:45 -0500 Received: from fllnx209.ext.ti.com ([198.47.19.16]:33160 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbcLFMUn (ORCPT ); Tue, 6 Dec 2016 07:20:43 -0500 Subject: Re: [PATCH v3 1/3] ARM: da850: fix infinite loop in clk_set_rate() To: Bartosz Golaszewski References: <1480932549-30811-1-git-send-email-bgolaszewski@baylibre.com> <1480932549-30811-2-git-send-email-bgolaszewski@baylibre.com> <689efaa1-d8d9-6937-5880-3ed7a1401268@ti.com> CC: Kevin Hilman , Michael Turquette , Peter Ujfalusi , Russell King , Viresh Kumar , Boris Brezillon , "Rafael J. Wysocki" , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Cyrille Pitchen , LKML , arm-soc , linux-pm From: Sekhar Nori Message-ID: Date: Tue, 6 Dec 2016 17:49:20 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2525 Lines: 61 On Tuesday 06 December 2016 05:28 PM, Bartosz Golaszewski wrote: > 2016-12-05 11:15 GMT+01:00 Sekhar Nori : >> On Monday 05 December 2016 03:39 PM, Bartosz Golaszewski wrote: >>> The aemif clock is added twice to the lookup table in da850.c. This >>> breaks the children list of pll0_sysclk3 as we're using the same list >>> links in struct clk. When calling clk_set_rate(), we get stuck in >>> propagate_rate(). >>> >>> Create a separate clock for nand, inheriting the rate of the aemif >>> clock and retrieve it in the davinci_nand module. >>> >>> Signed-off-by: Bartosz Golaszewski >>> --- >>> arch/arm/mach-davinci/da850.c | 7 ++++++- >>> 1 file changed, 6 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c >>> index e770c97..c008e5e 100644 >>> --- a/arch/arm/mach-davinci/da850.c >>> +++ b/arch/arm/mach-davinci/da850.c >>> @@ -367,6 +367,11 @@ static struct clk aemif_clk = { >>> .flags = ALWAYS_ENABLED, >>> }; >>> >>> +static struct clk aemif_nand_clk = { >>> + .name = "nand", >>> + .parent = &aemif_clk, >>> +}; >>> + >>> static struct clk usb11_clk = { >>> .name = "usb11", >>> .parent = &pll0_sysclk4, >>> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = { >>> CLK("da830-mmc.0", NULL, &mmcsd0_clk), >>> CLK("da830-mmc.1", NULL, &mmcsd1_clk), >>> CLK("ti-aemif", NULL, &aemif_clk), >>> - CLK(NULL, "aemif", &aemif_clk), >>> + CLK(NULL, "aemif", &aemif_nand_clk), >> >> Why use a NULL device name here? > > Hi Sekhar, > > there's an issue with this bit. I added an of_dev_auxdata entry to > da8xx-dt.c for the nand node, but it didn't work (the nand driver > could not get the clock). When I dug deeper, it turned out, the nand > node is created from aemif_probe() instead of from > da850_init_machine() and the lookup table is not passed as argument to > of_platform_populate(). > > There are two solutions: one is using "620000000.nand" as dev_id in > the clock lookup table, but that's ugly. The second is leaving dev_id > as NULL - I verified that the nand driver works correctly having only > the connector id. Please let me know which one you prefer or if you > have other ideas. Alright, I will take a look at whats going on here. This series will have to wait for v4.11 anyway. Thanks, Sekhar