From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shinya Kuribayashi Subject: [PATCH v2 14/22] i2c-designware: Initialize byte count variables just prior to being used Date: Fri, 06 Nov 2009 21:49:39 +0900 Message-ID: <4AF41B63.3020404@necel.com> References: <4AF419B6.1000802@necel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4AF419B6.1000802-jaWZhaxaiAMAvxtiuMwx3w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org, ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org As the driver and hardware always process the given data in parallel, then it would be better to initialize tx_limit, rx_limit and rx_valid variables just prior to being used. This will help us to send / receive as much data as possible. Signed-off-by: Shinya Kuribayashi Acked-by: Baruch Siach --- drivers/i2c/busses/i2c-designware.c | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c index e8e2212..c3702a8 100644 --- a/drivers/i2c/busses/i2c-designware.c +++ b/drivers/i2c/busses/i2c-designware.c @@ -360,8 +360,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; u32 intr_mask; - int tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR); - int rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR); + int tx_limit, rx_limit; u32 addr = msgs[dev->msg_write_idx].addr; u32 buf_len = dev->tx_buf_len; u8 *buf = dev->tx_buf;; @@ -389,6 +388,9 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) buf_len = msgs[dev->msg_write_idx].len; } + tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR); + rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR); + while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) { if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { writel(0x100, dev->base + DW_IC_DATA_CMD); @@ -418,7 +420,7 @@ i2c_dw_read(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; u32 addr = msgs[dev->msg_read_idx].addr; - int rx_valid = readl(dev->base + DW_IC_RXFLR); + int rx_valid; for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) { u32 len; @@ -439,6 +441,8 @@ i2c_dw_read(struct dw_i2c_dev *dev) buf = dev->rx_buf; } + rx_valid = readl(dev->base + DW_IC_RXFLR); + for (; len > 0 && rx_valid > 0; len--, rx_valid--) *buf++ = readl(dev->base + DW_IC_DATA_CMD); -- 1.6.5.2