From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= Subject: [PATCH v4 4/7] i2c: bcm2835: Can't support I2C_M_IGNORE_NAK Date: Mon, 3 Oct 2016 22:06:11 +0200 Message-ID: <1475525174-28604-5-git-send-email-noralf@tronnes.org> References: <1475525174-28604-1-git-send-email-noralf@tronnes.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: Received: from smtp.domeneshop.no ([194.63.252.55]:39204 "EHLO smtp.domeneshop.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753076AbcJCUGo (ORCPT ); Mon, 3 Oct 2016 16:06:44 -0400 In-Reply-To: <1475525174-28604-1-git-send-email-noralf@tronnes.org> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: wsa@the-dreams.de, swarren@wwwdotorg.org, eric@anholt.net Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= The controller can't support this flag, so remove it. Documentation/i2c/i2c-protocol states that all of the message is sent: I2C_M_IGNORE_NAK: Normally message is interrupted immediately if there is [NA] from the client. Setting this flag treats any [NA] as [A], and all of message is sent. >>From the BCM2835 ARM Peripherals datasheet: The ERR field is set when the slave fails to acknowledge either its address or a data byte written to it. So when the controller doesn't receive an ack, it sets ERR and raises an interrupt. In other words, the whole message is not sent. Signed-off-by: Noralf Trønnes Reviewed-by: Eric Anholt --- drivers/i2c/busses/i2c-bcm2835.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c index 54d510a..565ef69 100644 --- a/drivers/i2c/busses/i2c-bcm2835.c +++ b/drivers/i2c/busses/i2c-bcm2835.c @@ -212,10 +212,6 @@ static int bcm2835_i2c_xfer_msg(struct bcm2835_i2c_dev *i2c_dev, if (likely(!i2c_dev->msg_err)) return 0; - if ((i2c_dev->msg_err & BCM2835_I2C_S_ERR) && - (msg->flags & I2C_M_IGNORE_NAK)) - return 0; - dev_dbg(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err); if (i2c_dev->msg_err & BCM2835_I2C_S_ERR) -- 2.8.2