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-rw-r--r--drivers/i2c/busses/i2c-designware-core.c11
-rw-r--r--drivers/i2c/busses/i2c-designware-core.h2
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 21fbb340ad66..1f06c8e9934c 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -448,8 +448,14 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
cmd |= BIT(9);
if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
+
+ /* avoid rx buffer overrun */
+ if (rx_limit - dev->rx_outstanding <= 0)
+ break;
+
dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
rx_limit--;
+ dev->rx_outstanding++;
} else
dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
tx_limit--; buf_len--;
@@ -502,8 +508,10 @@ i2c_dw_read(struct dw_i2c_dev *dev)
rx_valid = dw_readl(dev, DW_IC_RXFLR);
- for (; len > 0 && rx_valid > 0; len--, rx_valid--)
+ for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
*buf++ = dw_readl(dev, DW_IC_DATA_CMD);
+ dev->rx_outstanding--;
+ }
if (len > 0) {
dev->status |= STATUS_READ_IN_PROGRESS;
@@ -561,6 +569,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
dev->msg_err = 0;
dev->status = STATUS_IDLE;
dev->abort_source = 0;
+ dev->rx_outstanding = 0;
ret = i2c_dw_wait_bus_not_busy(dev);
if (ret < 0)
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 9c1840ee09c7..e761ad18dd61 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -60,6 +60,7 @@
* @adapter: i2c subsystem adapter node
* @tx_fifo_depth: depth of the hardware tx fifo
* @rx_fifo_depth: depth of the hardware rx fifo
+ * @rx_outstanding: current master-rx elements in tx fifo
*/
struct dw_i2c_dev {
struct device *dev;
@@ -88,6 +89,7 @@ struct dw_i2c_dev {
u32 master_cfg;
unsigned int tx_fifo_depth;
unsigned int rx_fifo_depth;
+ int rx_outstanding;
};
#define ACCESS_SWAP 0x00000001