From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752814AbcFUSEr (ORCPT ); Tue, 21 Jun 2016 14:04:47 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:56961 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752212AbcFUSE3 (ORCPT ); Tue, 21 Jun 2016 14:04:29 -0400 From: Guenter Roeck To: Mark Brown Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Guenter Roeck , Markus Pargmann Subject: [PATCH] regmap-i2c: Use i2c block command only if register value width is 8 bit Date: Tue, 21 Jun 2016 11:04:23 -0700 Message-Id: <1466532263-23659-1-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 2.5.0 X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Chips with 16-bit registers don't usually work well with I2C block commands. For example, neither the LM75 datasheet nor the TMP102 datasheet mentions block command support, and in fact it does not work for any of those chips. Also, it is not clear how the block command would handle 16-bit SMBus operations in the fist place, since the data format associated with those commands is either little endian or big endian, which requires some kind of conversion to or from host byte order. Only use i2c block commands if both register and value width is 8 bit. Fixes: 29332534e2b6 ("regmap-i2c: Add smbus i2c block support") Cc: Markus Pargmann Signed-off-by: Guenter Roeck --- drivers/base/regmap/regmap-i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c index 1a8ec3b2b601..4735318f4268 100644 --- a/drivers/base/regmap/regmap-i2c.c +++ b/drivers/base/regmap/regmap-i2c.c @@ -259,7 +259,7 @@ static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c, { if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C)) return ®map_i2c; - else if (config->reg_bits == 8 && + else if (config->val_bits == 8 && config->reg_bits == 8 && i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) return ®map_i2c_smbus_i2c_block; -- 2.5.0