From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from sauhun.de ([88.99.104.3]:59953 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753165AbdHQOO5 (ORCPT ); Thu, 17 Aug 2017 10:14:57 -0400 From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, linux-input@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, Wolfram Sang Subject: [RFC PATCH v4 5/6] i2c: rcar: skip DMA if buffer is not safe Date: Thu, 17 Aug 2017 16:14:48 +0200 Message-Id: <20170817141449.23958-6-wsa+renesas@sang-engineering.com> In-Reply-To: <20170817141449.23958-1-wsa+renesas@sang-engineering.com> References: <20170817141449.23958-1-wsa+renesas@sang-engineering.com> Sender: linux-media-owner@vger.kernel.org List-ID: This HW is prone to races, so it needs to setup new messages in irq context. That means we can't alloc bounce buffers if a message buffer is not DMA safe. So, in that case, simply fall back to PIO. Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-rcar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 93c1a54981df08..5654a7142bffec 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -359,7 +359,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv) int len; /* Do not use DMA if it's not available or for messages < 8 bytes */ - if (IS_ERR(chan) || msg->len < 8) + if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE)) return; if (read) { -- 2.11.0