Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755799AbbBJMw4 (ORCPT ); Tue, 10 Feb 2015 07:52:56 -0500 Received: from mail-la0-f44.google.com ([209.85.215.44]:35501 "EHLO mail-la0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755058AbbBJMwy (ORCPT ); Tue, 10 Feb 2015 07:52:54 -0500 MIME-Version: 1.0 In-Reply-To: <1422645610-3052-1-git-send-email-stefan.wahren@i2se.com> References: <1422645610-3052-1-git-send-email-stefan.wahren@i2se.com> Date: Tue, 10 Feb 2015 10:52:52 -0200 Message-ID: Subject: Re: [PATCH V2 RESEND] clk: mxs: Fix invalid 32-bit access to frac registers From: Fabio Estevam To: Stefan Wahren Cc: Mike Turquette , Marek Vasut , Zhi Li , Sascha Hauer , harald@ccbib.org, Shawn Guo , linux-kernel , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1601 Lines: 48 Hi Stefan, On Fri, Jan 30, 2015 at 5:20 PM, Stefan Wahren wrote: > According to i.MX23 and i.MX28 reference manual [1],[2] the fractional > clock control register is 32-bit wide, but is separated in 4 parts. > So write instructions must not apply to more than 1 part at once. > > The clk init for the i.MX28 violates this restriction and all the other > accesses on that register suggest that there isn't such a restriction. > > This patch restricts the access to this register to byte instructions and > extends the comment in the init functions. > > Btw the imx23 init now uses a R-M-W sequence just like imx28 init > to avoid any clock glitches. > > The changes has been tested with a i.MX23 and a i.MX28 board. > > [1] - http://cache.freescale.com/files/dsp/doc/ref_manual/IMX23RM.pdf > [2] - http://cache.freescale.com/files/dsp/doc/ref_manual/MCIMX28RM.pdf > > Signed-off-by: Stefan Wahren > Reviewed-by: Marek Vasut > --- > > Changes in V2: > - use relaxed access operations in clk-ref With this patch applied mx28evk cannot probe SPI NOR flash: m25p80 spi1.0: unrecognized JEDEC id bytes: bf, 24, 40 Reverting it from linux-next, then the SPI NOR probe correctly. m25p80 spi1.0: sst25vf016b (2048 Kbytes) Any ideas? Thanks for the suggestion, Marek! Regards, Fabio Estevam -- 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/