From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] i2c: rk3x: fix bug that cause transfer fails in master receive mode Date: Thu, 21 Aug 2014 22:04:31 +0400 Message-ID: <53F634AF.1010303@cogentembedded.com> References: <1408643457-7126-1-git-send-email-addy.ke@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1408643457-7126-1-git-send-email-addy.ke@rock-chips.com> Sender: linux-kernel-owner@vger.kernel.org To: Addy Ke , wsa@the-dreams.de, max.schwarz@online.de, heiko@sntech.de, olof@lixom.net, dianders@chromium.org Cc: huangtao@rock-chips.com, hl@rock-chips.com, yzq@rock-chips.com, zyw@rock-chips.com, linux-kernel@vger.kernel.org, kever.yang@rock-chips.com, linux-rockchip@lists.infradead.org, xjq@rock-chips.com, linux-i2c@vger.kernel.org, caesar.wang@rock-chips.com, cf@rock-chips.com, hj@rock-chips.com, zhengsq@rock-chips.com, linux-arm-kernel@lists.infradead.org List-Id: linux-i2c@vger.kernel.org Hello. On 08/21/2014 09:50 PM, Addy Ke wrote: > In rk3x SOC, the I2C controller can receive/transmit up to 32 bytes data > in one transaction, so the size of data to be write/read to/from > TXDATAx/RXDATAx must be less than or equal 32 bytes at a time. > Test on pinky board, elan receive 158 bytes data. > Signed-off-by: Addy Ke > --- > drivers/i2c/busses/i2c-rk3x.c | 3 +++ > 1 file changed, 3 insertions(+) > diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c > index 69e1185..dc0aa64 100644 > --- a/drivers/i2c/busses/i2c-rk3x.c > +++ b/drivers/i2c/busses/i2c-rk3x.c > @@ -323,6 +323,9 @@ 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 */ > + len = (len > 32) ? 32 : len; Why not min(len, 32)? Or even: if (len > 32) len = 32; WBR, Sergei