From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752111AbeBFNxj (ORCPT ); Tue, 6 Feb 2018 08:53:39 -0500 Received: from lelnx193.ext.ti.com ([198.47.27.77]:57072 "EHLO lelnx193.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751995AbeBFNxU (ORCPT ); Tue, 6 Feb 2018 08:53:20 -0500 Subject: Re: [PATCH] ARM: dts: da850-evm: add clock properties to the nand node To: Bartosz Golaszewski CC: Bartosz Golaszewski , Kevin Hilman , Rob Herring , Mark Rutland , Russell King , David Lechner , arm-soc , linux-devicetree , LKML References: <20180205155222.22189-1-brgl@bgdev.pl> <3f171f6a-bcea-65ec-d56d-f6ae24660f34@ti.com> From: Sekhar Nori Message-ID: <54dbdb98-e0e4-c8c9-fec4-2f050745d9be@ti.com> Date: Tue, 6 Feb 2018 19:21:54 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 06 February 2018 06:38 PM, Bartosz Golaszewski wrote: > 2018-02-06 12:07 GMT+01:00 Sekhar Nori : >> On Monday 05 February 2018 09:22 PM, Bartosz Golaszewski wrote: >>> From: Bartosz Golaszewski >>> >>> Make nand work with the common clock framework by specifying which >>> clock should be used and what name to look up. >>> >>> Signed-off-by: Bartosz Golaszewski >>> --- >>> arch/arm/boot/dts/da850-evm.dts | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/arch/arm/boot/dts/da850-evm.dts b/arch/arm/boot/dts/da850-evm.dts >>> index a86a8a1816f2..2602ad8e99ee 100644 >>> --- a/arch/arm/boot/dts/da850-evm.dts >>> +++ b/arch/arm/boot/dts/da850-evm.dts >>> @@ -296,6 +296,9 @@ >>> reg = <0 0x02000000 0x02000000 >>> 1 0x00000000 0x00008000>; >>> >>> + clocks = <&psc0 3>; >>> + clock-names = "aemif"; >> >> Looks like this is being added only to satisfy the devm_clk_get() call >> in nand_davinci_probe() which I think is superfluous since we also >> enable the same clock in aemif_probe(). >> >> Perhaps the better solution is to drip the clk code in >> drivers/mtd/nand/davinci_nand.c and shift legacy code to start using >> drivers/memory/aemif.c as well? This way we can also drop >> arch/arm/mach-davinci/aemif.c >> >> Thanks, >> Sekhar > > Yes, this sounds good, but I think we should leave it for later as an > additional improvement, once everything else is in place. I think > these patches should be applied together with David's series in order > to not break the support on davinci boards and the aemif work would go > in later as a follow-up. How about that? No, I dont think we should add temporary hacks to DT to work around driver issues (I do think its a hack since the clock belongs to aemif module not NAND flash). An easier driver hack might be to not treat devm_clk_get() failure in davinci_nand.c as catastrophic. It will safely fail in DT case and we should get the clock in legacy boot case. I think we are looking at a driver update dependency anyway. > > Also: I don't have any keystone board to test whether such changes > don't break the nand support there. Would you be able to test this? Yes, I have access to those boards. Thanks, Sekhar