Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
as needed. Remove BUG() and make Rx and Tx case handling
similar. Add WARN_ON_ONCE check for non-zero rx_fifo_avail
in tegra_i2c_empty_rx_fifo() and return new error
I2C_ERR_UNEXPECTED_STATUS.

Signed-off-by: Bitan Biswas <bbis...@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 0596c12..2c8f051 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -73,6 +73,7 @@
 #define I2C_ERR_NO_ACK                         BIT(0)
 #define I2C_ERR_ARBITRATION_LOST               BIT(1)
 #define I2C_ERR_UNKNOWN_INTERRUPT              BIT(2)
+#define I2C_ERR_UNEXPECTED_STATUS              BIT(3)
 
 #define PACKET_HEADER0_HEADER_SIZE_SHIFT       28
 #define PACKET_HEADER0_PACKET_ID_SHIFT         16
@@ -516,15 +517,15 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev 
*i2c_dev)
         */
        if (rx_fifo_avail > 0 &&
            (buf_remaining > 0 && buf_remaining < BYTES_PER_FIFO_WORD)) {
-               BUG_ON(buf_remaining > 3);
                val = i2c_readl(i2c_dev, I2C_RX_FIFO);
                val = cpu_to_le32(val);
                memcpy(buf, &val, buf_remaining);
                buf_remaining = 0;
                rx_fifo_avail--;
        }
+       if (WARN_ON_ONCE(rx_fifo_avail))
+               return -EINVAL;
 
-       BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
        i2c_dev->msg_buf_remaining = buf_remaining;
        i2c_dev->msg_buf = buf;
 
@@ -582,7 +583,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev 
*i2c_dev)
         */
        if (tx_fifo_avail > 0 &&
            (buf_remaining > 0 && buf_remaining < BYTES_PER_FIFO_WORD)) {
-               BUG_ON(buf_remaining > 3);
                memcpy(&val, buf, buf_remaining);
                val = le32_to_cpu(val);
 
@@ -848,10 +848,16 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
 
        if (!i2c_dev->is_curr_dma_xfer) {
                if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
-                       if (i2c_dev->msg_buf_remaining)
-                               tegra_i2c_empty_rx_fifo(i2c_dev);
-                       else
-                               BUG();
+                       if (i2c_dev->msg_buf_remaining) {
+                               if (tegra_i2c_empty_rx_fifo(i2c_dev)) {
+                                       i2c_dev->msg_err |=
+                                               I2C_ERR_UNEXPECTED_STATUS;
+                                       goto err;
+                               }
+                       } else {
+                               tegra_i2c_mask_irq(i2c_dev,
+                                                  I2C_INT_RX_FIFO_DATA_REQ);
+                       }
                }
 
                if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
@@ -877,7 +883,10 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
        if (status & I2C_INT_PACKET_XFER_COMPLETE) {
                if (i2c_dev->is_curr_dma_xfer)
                        i2c_dev->msg_buf_remaining = 0;
-               BUG_ON(i2c_dev->msg_buf_remaining);
+               if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
+                       i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
+                       goto err;
+               }
                complete(&i2c_dev->msg_complete);
        }
        goto done;
-- 
2.7.4

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