-----Original Message----- From: linux-i2c-owner@xxxxxxxxxxxxxxx [mailto:linux-i2c-owner@xxxxxxxxxxxxxxx] On Behalf Of Shinya Kuribayashi Sent: Monday, October 12, 2009 9:54 PM To: baruch@xxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx Cc: ben-linux@xxxxxxxxx; linux-mips@xxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Subject: [PATCH 14/16] i2c-designware: Deferred FIFO-data-counting variables initialization As the driver and hardware always process the given data in parallel, it would be better to initialize those {tx,rx}_limit or rx_valid variables just prior to be used. This will help to send/receive data as much as possible. Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@xxxxxxxxx> --- 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 b3152c2..f7ea032 100644 --- a/drivers/i2c/busses/i2c-designware.c +++ b/drivers/i2c/busses/i2c-designware.c @@ -359,8 +359,7 @@ 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;; @@ -386,6 +385,9 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
