Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752160AbdLDQCI (ORCPT ); Mon, 4 Dec 2017 11:02:08 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33248 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752930AbdLDQCB (ORCPT ); Mon, 4 Dec 2017 11:02:01 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bartosz Golaszewski , Andy Shevchenko Subject: [PATCH 4.9 21/38] eeprom: at24: correctly set the size for at24mac402 Date: Mon, 4 Dec 2017 17:00:01 +0100 Message-Id: <20171204160008.268160875@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171204160007.448534903@linuxfoundation.org> References: <20171204160007.448534903@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 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: 1698 Lines: 47 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bartosz Golaszewski commit 5478e478eee3b096b8d998d4ed445da30da2dfbc upstream. There's an ilog2() expansion in AT24_DEVICE_MAGIC() which rounds down the actual size of EUI-48 byte array in at24mac402 eeproms to 4 from 6, making it impossible to read it all. Fix it by manually adjusting the value in probe(). This patch contains a temporary fix that is suitable for stable branches. Eventually we'll probably remove the call to ilog2() while converting the magic values to actual structs. Fixes: 0b813658c115 ("eeprom: at24: add support for at24mac series") Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman --- drivers/misc/eeprom/at24.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -639,6 +639,16 @@ static int at24_probe(struct i2c_client dev_warn(&client->dev, "page_size looks suspicious (no power of 2)!\n"); + /* + * REVISIT: the size of the EUI-48 byte array is 6 in at24mac402, while + * the call to ilog2() in AT24_DEVICE_MAGIC() rounds it down to 4. + * + * Eventually we'll get rid of the magic values altoghether in favor of + * real structs, but for now just manually set the right size. + */ + if (chip.flags & AT24_FLAG_MAC && chip.byte_len == 4) + chip.byte_len = 6; + /* Use I2C operations unless we're stuck with SMBus extensions. */ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { if (chip.flags & AT24_FLAG_ADDR16)