Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751371AbdL1HOu (ORCPT ); Thu, 28 Dec 2017 02:14:50 -0500 Received: from 9pmail.ess.barracuda.com ([64.235.150.224]:52072 "EHLO 9pmail.ess.barracuda.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbdL1HOt (ORCPT ); Thu, 28 Dec 2017 02:14:49 -0500 Subject: Re: [PATCH 1/2] nvmem: add driver for JZ4780 efuse To: Mathieu Malaterre , CC: PrasannaKumar Muralidharan , "Srinivas Kandagatla" , Rob Herring , Mark Rutland , Ralf Baechle , "David S. Miller" , "Mauro Carvalho Chehab" , Greg Kroah-Hartman , Randy Dunlap , "Thomas Gleixner" , Paul Cercueil , "Linus Walleij" , Harvey Hunt , James Hogan , Krzysztof Kozlowski , , , References: <20171227122722.5219-1-malat@debian.org> <20171227122722.5219-2-malat@debian.org> From: Marcin Nowakowski Message-ID: Date: Thu, 28 Dec 2017 08:13:33 +0100 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: <20171227122722.5219-2-malat@debian.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.159.77] X-BESS-ID: 1514445242-637138-32434-176451-5 X-BESS-VER: 2017.16-r1712230000 X-BESS-Apparent-Source-IP: 12.201.5.28 X-BESS-Outbound-Spam-Score: 0.20 X-BESS-Outbound-Spam-Report: Code version 3.2, rules version 3.2.2.188423 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------- 0.20 BSF_SC7_SA298e META: Custom Rule SA298e 0.00 BSF_BESS_OUTBOUND META: BESS Outbound X-BESS-Outbound-Spam-Status: SCORE=0.20 using account:ESS59374 scores of KILL_LEVEL=7.0 tests=BSF_SC7_SA298e, BSF_BESS_OUTBOUND X-BESS-BRTS-Status: 1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1623 Lines: 55 Hi Mathieu, PrasannaKumar, On 27.12.2017 13:27, Mathieu Malaterre wrote: > From: PrasannaKumar Muralidharan > > This patch brings support for the JZ4780 efuse. Currently it only expose > a read only access to the entire 8K bits efuse memory. > > Tested-by: Mathieu Malaterre > Signed-off-by: PrasannaKumar Muralidharan > --- > + > +/* main entry point */ > +static int jz4780_efuse_read(void *context, unsigned int offset, > + void *val, size_t bytes) > +{ > + static const int nsegments = sizeof(segments) / sizeof(*segments); > + struct jz4780_efuse *efuse = context; > + char buf[32]; > + char *cur = val; > + int i; > + /* PM recommends read/write each segment separately */ > + for (i = 0; i < nsegments; ++i) { > + unsigned int *segment = segments[i]; > + unsigned int lpos = segment[0]; > + unsigned int buflen = segment[1] / 8; > + unsigned int ncount = buflen / 32; > + unsigned int remain = buflen % 32; > + int j; This doesn't look right, as offset & bytes are completely ignored. This means it will return data from an offset other than requested and may also overrun the provided output buffer? > + /* EFUSE can read or write maximum 256bit in each time */ > + for (j = 0; j < ncount ; ++j) { > + jz4780_efuse_read_32bytes(efuse, buf, lpos); > + memcpy(cur, buf, sizeof(buf)); > + cur += sizeof(buf); > + lpos += sizeof(buf); > + } > + if (remain) { > + jz4780_efuse_read_32bytes(efuse, buf, lpos); > + memcpy(cur, buf, remain); > + cur += remain; > + } > + } > + > + return 0; > +} Marcin