From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753549AbdK0VGT (ORCPT ); Mon, 27 Nov 2017 16:06:19 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35946 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753284AbdK0VGR (ORCPT ); Mon, 27 Nov 2017 16:06:17 -0500 X-Google-Smtp-Source: AGs4zMagGGvt4gs+5Rh/oGNENj6MjlqoalR/gw0RydIDV/vm4ybBFidv3tlKacUMsJnc+CbPfwsM6Q== From: Bartosz Golaszewski To: Heiner Kallweit , Claudiu Beznea Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski , stable@vger.kernel.org Subject: [PATCH] eeprom: at24: correctly set the size for at24mac402 Date: Mon, 27 Nov 2017 22:06:13 +0100 Message-Id: <20171127210613.9140-1-brgl@bgdev.pl> X-Mailer: git-send-email 2.15.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Cc: stable@vger.kernel.org Fixes: 0b813658c115 ("eeprom: at24: add support for at24mac series") Signed-off-by: Bartosz Golaszewski --- drivers/misc/eeprom/at24.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index e0b4b36ef010..783244b485cc 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -730,6 +730,16 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) 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) -- 2.15.0