From mboxrd@z Thu Jan 1 00:00:00 1970 From: Addy Ke Subject: [PATCH v2] i2c: rk3x: fix bug that cause transfer fails in maste receive mode Date: Fri, 22 Aug 2014 05:38:27 +0800 Message-ID: <1408657107-8715-1-git-send-email-addy.ke@rock-chips.com> References: <0001-i2c-rk3x-fix-bug-that-cause-transfer-fails-in-master.patch> Return-path: In-Reply-To: <0001-i2c-rk3x-fix-bug-that-cause-transfer-fails-in-master.patch> Sender: linux-kernel-owner@vger.kernel.org To: wsa@the-dreams.de, max.schwarz@online.de, heiko@sntech.de, olof@lixom.net, dianders@chromium.org Cc: sergei.shtylyov@cogentembedded.com, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, cf@rock-chips.com, xjq@rock-chips.com, huangtao@rock-chips.com, zyw@rock-chips.com, yzq@rock-chips.com, hj@rock-chips.com, kever.yang@rock-chips.com, hl@rock-chips.com, caesar.wang@rock-chips.com, zhengsq@rock-chips.com, Addy Ke List-Id: linux-i2c@vger.kernel.org In rk3x SOC, the I2C controller can receive/transmit up to 32 bytes data in one chunk, so the size of data to be write/read to/from TXDATAx/RXDATAx must be less than or equal 32 bytes at a time. Tested on rk3288-pinky board, elan receive 158 bytes data. Acked-by: Max Schwarz Signed-off-by: Addy Ke --- Changes in v2: - Use cleaner syntax as suggested by Sergei. - Update commit message as suggested by Wolfram. drivers/i2c/busses/i2c-rk3x.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index 69e1185..806724a 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -323,6 +323,10 @@ static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd) /* ack interrupt */ i2c_writel(i2c, REG_INT_MBRF, REG_IPD); + /* Can only handle a maximum of 32 bytes at a time */ + if (unlikely(len > 32)) + len = 32; + /* read the data from receive buffer */ for (i = 0; i < len; ++i) { if (i % 4 == 0) -- 1.8.3.2