07.06.2019 15:08, Dmitry Osipenko пишет:
> 07.06.2019 14:55, Bitan Biswas пишет:
>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>> as needed. Replace BUG() with error handling code.
>> Define I2C_ERR_UNEXPECTED_STATUS for error handling.
>>
>> Signed-off-by: Bitan Biswas <bbiswas@xxxxxxxxxx>
>> ---
>> drivers/i2c/busses/i2c-tegra.c | 15 ++++++++-------
>> 1 file changed, 8 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>> index 4dfb4c1..c407bd7 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
>> @@ -515,7 +516,6 @@ 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);
>> val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>> val = cpu_to_le32(val);
>> memcpy(buf, &val, buf_remaining);
>> @@ -523,7 +523,6 @@ 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);
>> i2c_dev->msg_buf_remaining = buf_remaining;
>> i2c_dev->msg_buf = buf;
>>
>> @@ -581,7 +580,6 @@ 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);
>> memcpy(&val, buf, buf_remaining);
>> val = le32_to_cpu(val);
>>
>> @@ -847,10 +845,13 @@ 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)
>> + if (i2c_dev->msg_buf_remaining) {
>> tegra_i2c_empty_rx_fifo(i2c_dev);
>> - else
>> - BUG();
>> + } else {
>> + dev_err(i2c_dev->dev, "unexpected rx data request\n");
>> + i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
>> + goto err;
>> + }
>> }
>>
>> if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
>> @@ -876,7 +877,7 @@ 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);
>> + WARN_ON_ONCE(i2c_dev->msg_buf_remaining);
>> complete(&i2c_dev->msg_complete);
>> }
>> goto done;
>>
>
> Very nice, thank you very much! BTW, I think it may worth to add another
> patch that will reset hardware state in a case of the warning since we
> know that something gone wrong.
>
> Reviewed-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>
Something like that:
complete(&i2c_dev->msg_complete);
if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining))
goto err;
