Commit 57ca968b authored by Bitan Biswas's avatar Bitan Biswas Committed by Wolfram Sang
Browse files

i2c: tegra: remove BUG() macro



The usage of BUG() macro is generally discouraged in kernel, unless
it's a problem that results in a physical damage or loss of data.
This patch removes unnecessary BUG() macros and replaces the rest
with warning.
Signed-off-by: default avatarBitan Biswas <bbiswas@nvidia.com>
Reviewed-by: default avatarDmitry Osipenko <digetx@gmail.com>
Tested-by: default avatarDmitry Osipenko <digetx@gmail.com>
Acked-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 9be1485a
......@@ -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_RX_BUFFER_OVERFLOW BIT(3)
#define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
#define PACKET_HEADER0_PACKET_ID_SHIFT 16
......@@ -489,6 +490,13 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
size_t buf_remaining = i2c_dev->msg_buf_remaining;
int words_to_transfer;
/*
* Catch overflow due to message fully sent
* before the check for RX FIFO availability.
*/
if (WARN_ON_ONCE(!(i2c_dev->msg_buf_remaining)))
return -EINVAL;
if (i2c_dev->hw->has_mst_fifo) {
val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
rx_fifo_avail = (val & I2C_MST_FIFO_STATUS_RX_MASK) >>
......@@ -515,7 +523,11 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
* prevent overwriting past the end of buf
*/
if (rx_fifo_avail > 0 && buf_remaining > 0) {
BUG_ON(buf_remaining > 3);
/*
* buf_remaining > 3 check not needed as rx_fifo_avail == 0
* when (words_to_transfer was > rx_fifo_avail) earlier
* in this function.
*/
val = i2c_readl(i2c_dev, I2C_RX_FIFO);
val = cpu_to_le32(val);
memcpy(buf, &val, buf_remaining);
......@@ -523,7 +535,10 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
rx_fifo_avail--;
}
BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
/* RX FIFO must be drained, otherwise it's an Overflow case. */
if (WARN_ON_ONCE(rx_fifo_avail))
return -EINVAL;
i2c_dev->msg_buf_remaining = buf_remaining;
i2c_dev->msg_buf = buf;
......@@ -581,7 +596,11 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
* boundary and fault.
*/
if (tx_fifo_avail > 0 && buf_remaining > 0) {
BUG_ON(buf_remaining > 3);
/*
* buf_remaining > 3 check not needed as tx_fifo_avail == 0
* when (words_to_transfer was > tx_fifo_avail) earlier
* in this function for non-zero words_to_transfer.
*/
memcpy(&val, buf, buf_remaining);
val = le32_to_cpu(val);
......@@ -847,10 +866,15 @@ 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 (tegra_i2c_empty_rx_fifo(i2c_dev)) {
/*
* Overflow error condition: message fully sent,
* with no XFER_COMPLETE interrupt but hardware
* asks to transfer more.
*/
i2c_dev->msg_err |= I2C_ERR_RX_BUFFER_OVERFLOW;
goto err;
}
}
if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
......@@ -876,7 +900,14 @@ 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);
/*
* Underflow error condition: XFER_COMPLETE before message
* fully sent.
*/
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;
......
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