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| author | Shinya Kuribayashi <shinya.kuribayashi@necel.com> | 2009-11-06 21:49:39 +0900 |
|---|---|---|
| committer | Ben Dooks <ben-linux@fluff.org> | 2009-12-09 00:19:11 +0000 |
| commit | ae72222d03fea3ff561e2a3aee483ef7bd1a2bbb (patch) | |
| tree | e08e9e5d81fbbec97d2c6b47a09c1e7bf4be24b5 /drivers/i2c/busses/i2c-designware.c | |
| parent | 26ea15b1f584de02bc85e9c3968d523386332f65 (diff) | |
| download | lwn-ae72222d03fea3ff561e2a3aee483ef7bd1a2bbb.tar.gz lwn-ae72222d03fea3ff561e2a3aee483ef7bd1a2bbb.zip | |
i2c-designware: Initialize byte count variables just prior to being used
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 <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-designware.c')
| -rw-r--r-- | 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 e8e2212d576e..c3702a8647cb 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); |