2019-06-10 05:09:23

by Bitan Biswas

[permalink] [raw]
Subject: [PATCH V3 1/6] i2c: tegra: clean up macros

Clean up macros by:
1) removing unused macros
2) replace constants by macro BIT()

Signed-off-by: Bitan Biswas <[email protected]>
Reviewed-by: Dmitry Osipenko <[email protected]>
---
drivers/i2c/busses/i2c-tegra.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 1dbba39..00692d8 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -54,20 +54,15 @@
#define I2C_INT_STATUS 0x068
#define I2C_INT_BUS_CLR_DONE BIT(11)
#define I2C_INT_PACKET_XFER_COMPLETE BIT(7)
-#define I2C_INT_ALL_PACKETS_XFER_COMPLETE BIT(6)
-#define I2C_INT_TX_FIFO_OVERFLOW BIT(5)
-#define I2C_INT_RX_FIFO_UNDERFLOW BIT(4)
#define I2C_INT_NO_ACK BIT(3)
#define I2C_INT_ARBITRATION_LOST BIT(2)
#define I2C_INT_TX_FIFO_DATA_REQ BIT(1)
#define I2C_INT_RX_FIFO_DATA_REQ BIT(0)
#define I2C_CLK_DIVISOR 0x06c
#define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT 16
-#define I2C_CLK_MULTIPLIER_STD_FAST_MODE 8

#define DVC_CTRL_REG1 0x000
#define DVC_CTRL_REG1_INTR_EN BIT(10)
-#define DVC_CTRL_REG2 0x004
#define DVC_CTRL_REG3 0x008
#define DVC_CTRL_REG3_SW_PROG BIT(26)
#define DVC_CTRL_REG3_I2C_DONE_INTR_EN BIT(30)
@@ -75,24 +70,21 @@
#define DVC_STATUS_I2C_DONE_INTR BIT(30)

#define I2C_ERR_NONE 0x00
-#define I2C_ERR_NO_ACK 0x01
-#define I2C_ERR_ARBITRATION_LOST 0x02
-#define I2C_ERR_UNKNOWN_INTERRUPT 0x04
+#define I2C_ERR_NO_ACK BIT(0)
+#define I2C_ERR_ARBITRATION_LOST BIT(1)
+#define I2C_ERR_UNKNOWN_INTERRUPT BIT(2)

#define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
#define PACKET_HEADER0_PACKET_ID_SHIFT 16
#define PACKET_HEADER0_CONT_ID_SHIFT 12
#define PACKET_HEADER0_PROTOCOL_I2C BIT(4)

-#define I2C_HEADER_HIGHSPEED_MODE BIT(22)
#define I2C_HEADER_CONT_ON_NAK BIT(21)
-#define I2C_HEADER_SEND_START_BYTE BIT(20)
#define I2C_HEADER_READ BIT(19)
#define I2C_HEADER_10BIT_ADDR BIT(18)
#define I2C_HEADER_IE_ENABLE BIT(17)
#define I2C_HEADER_REPEAT_START BIT(16)
#define I2C_HEADER_CONTINUE_XFER BIT(15)
-#define I2C_HEADER_MASTER_ADDR_SHIFT 12
#define I2C_HEADER_SLAVE_ADDR_SHIFT 1

#define I2C_BUS_CLEAR_CNFG 0x084
@@ -106,8 +98,6 @@

#define I2C_CONFIG_LOAD 0x08C
#define I2C_MSTR_CONFIG_LOAD BIT(0)
-#define I2C_SLV_CONFIG_LOAD BIT(1)
-#define I2C_TIMEOUT_CONFIG_LOAD BIT(2)

#define I2C_CLKEN_OVERRIDE 0x090
#define I2C_MST_CORE_CLKEN_OVR BIT(0)
@@ -133,7 +123,6 @@
#define I2C_STANDARD_MODE 100000
#define I2C_FAST_MODE 400000
#define I2C_FAST_PLUS_MODE 1000000
-#define I2C_HS_MODE 3500000

/* Packet header size in bytes */
#define I2C_PACKET_HEADER_SIZE 12
--
2.7.4


2019-06-10 05:09:33

by Bitan Biswas

[permalink] [raw]
Subject: [PATCH V3 2/6] i2c: tegra: remove unnecessary variable init

Remove variable initializations in functions that
are followed by assignments before use

Signed-off-by: Bitan Biswas <[email protected]>
Reviewed-by: Dmitry Osipenko <[email protected]>
---
drivers/i2c/busses/i2c-tegra.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 00692d8..f7116b7 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -689,7 +689,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
u32 val;
int err;
u32 clk_divisor, clk_multiplier;
- u32 tsu_thd = 0;
+ u32 tsu_thd;
u8 tlow, thigh;

err = pm_runtime_get_sync(i2c_dev->dev);
@@ -1218,7 +1218,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
int i;
- int ret = 0;
+ int ret;

ret = pm_runtime_get_sync(i2c_dev->dev);
if (ret < 0) {
@@ -1489,7 +1489,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
void __iomem *base;
phys_addr_t base_phys;
int irq;
- int ret = 0;
+ int ret;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base_phys = res->start;
--
2.7.4

2019-06-10 05:09:36

by Bitan Biswas

[permalink] [raw]
Subject: [PATCH V3 3/6] i2c: tegra: fix alignment and spacing violations

Fix checkpatch.pl alignment and blank line check(s) in i2c-tegra.c

Signed-off-by: Bitan Biswas <[email protected]>
Reviewed-by: Dmitry Osipenko <[email protected]>
---
drivers/i2c/busses/i2c-tegra.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index f7116b7..2d381de 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -295,7 +295,7 @@ static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
* to the I2C block inside the DVC block
*/
static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
- unsigned long reg)
+ unsigned long reg)
{
if (i2c_dev->is_dvc)
reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
@@ -303,7 +303,7 @@ static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
}

static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
- unsigned long reg)
+ unsigned long reg)
{
writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));

@@ -318,13 +318,13 @@ static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
}

static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
- unsigned long reg, int len)
+ unsigned long reg, int len)
{
writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}

static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
- unsigned long reg, int len)
+ unsigned long reg, int len)
{
readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}
@@ -669,10 +669,11 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
if (in_interrupt())
err = readl_poll_timeout_atomic(addr, val, val == 0,
- 1000, I2C_CONFIG_LOAD_TIMEOUT);
+ 1000,
+ I2C_CONFIG_LOAD_TIMEOUT);
else
- err = readl_poll_timeout(addr, val, val == 0,
- 1000, I2C_CONFIG_LOAD_TIMEOUT);
+ err = readl_poll_timeout(addr, val, val == 0, 1000,
+ I2C_CONFIG_LOAD_TIMEOUT);

if (err) {
dev_warn(i2c_dev->dev,
@@ -1013,7 +1014,8 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
}

static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
- struct i2c_msg *msg, enum msg_end_type end_state)
+ struct i2c_msg *msg,
+ enum msg_end_type end_state)
{
u32 packet_header;
u32 int_mask;
@@ -1150,9 +1152,8 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
if (err)
return err;

- time_left = wait_for_completion_timeout(
- &i2c_dev->dma_complete,
- msecs_to_jiffies(xfer_time));
+ time_left = wait_for_completion_timeout(&i2c_dev->dma_complete,
+ msecs_to_jiffies(xfer_time));
if (time_left == 0) {
dev_err(i2c_dev->dev, "DMA transfer timeout\n");
dmaengine_terminate_sync(i2c_dev->msg_read ?
@@ -1214,7 +1215,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
}

static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
- int num)
+ int num)
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
int i;
@@ -1260,14 +1261,15 @@ static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
{
struct device_node *np = i2c_dev->dev->of_node;
int ret;
+ bool multi_mode;

ret = of_property_read_u32(np, "clock-frequency",
- &i2c_dev->bus_clk_rate);
+ &i2c_dev->bus_clk_rate);
if (ret)
i2c_dev->bus_clk_rate = 100000; /* default clock rate */

- i2c_dev->is_multimaster_mode = of_property_read_bool(np,
- "multi-master");
+ multi_mode = of_property_read_bool(np, "multi-master");
+ i2c_dev->is_multimaster_mode = multi_mode;
}

static const struct i2c_algorithm tegra_i2c_algo = {
@@ -1611,7 +1613,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
}

ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
- tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
+ tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
goto release_dma;
@@ -1704,6 +1706,7 @@ static const struct dev_pm_ops tegra_i2c_pm = {
SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
NULL)
};
+
#define TEGRA_I2C_PM (&tegra_i2c_pm)
#else
#define TEGRA_I2C_PM NULL
--
2.7.4

2019-06-10 05:09:39

by Bitan Biswas

[permalink] [raw]
Subject: [PATCH V3 4/6] i2c: tegra: add spinlock definition comment

Fix checkpatch.pl CHECK as follows:
CHECK: spinlock_t definition without comment
+ spinlock_t xfer_lock;

Signed-off-by: Bitan Biswas <[email protected]>
Reviewed-by: Dmitry Osipenko <[email protected]>
---
drivers/i2c/busses/i2c-tegra.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 2d381de..bececa6 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -269,6 +269,7 @@ struct tegra_i2c_dev {
u32 bus_clk_rate;
u16 clk_divisor_non_hs_mode;
bool is_multimaster_mode;
+ /* xfer_lock: lock to serialize transfer submission and processing */
spinlock_t xfer_lock;
struct dma_chan *tx_dma_chan;
struct dma_chan *rx_dma_chan;
--
2.7.4

2019-06-10 05:09:58

by Bitan Biswas

[permalink] [raw]
Subject: [PATCH V3 5/6] i2c: tegra: fix msleep warning

Fix checkpatch.pl WARNING for delay of approximately 1msec
in flush i2c FIFO polling loop by using usleep_range(1000, 2000):
WARNING: msleep < 20ms can sleep for up to 20ms; see ...
Documentation/timers/timers-howto.txt
+ msleep(1);

Signed-off-by: Bitan Biswas <[email protected]>
Reviewed-by: Dmitry Osipenko <[email protected]>
---
drivers/i2c/busses/i2c-tegra.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index bececa6..4dfb4c1 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -476,7 +476,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
return -ETIMEDOUT;
}
- msleep(1);
+ usleep_range(1000, 2000);
}
return 0;
}
--
2.7.4

2019-06-10 05:11:18

by Bitan Biswas

[permalink] [raw]
Subject: [PATCH V3 6/6] i2c: tegra: remove BUG, BUG_ON

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 <[email protected]>
---
drivers/i2c/busses/i2c-tegra.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 4dfb4c1..d9e99b4 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 +877,10 @@ 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

2019-06-10 10:34:24

by Dmitry Osipenko

[permalink] [raw]
Subject: Re: [PATCH V3 6/6] i2c: tegra: remove BUG, BUG_ON

10.06.2019 8:08, 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 <[email protected]>
> ---
> drivers/i2c/busses/i2c-tegra.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 4dfb4c1..d9e99b4 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 +877,10 @@ 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;
>

It looks nearly ideal now, although there is still one thing that could
be improved. We're going to print a error message in a case of RX and
spew a warning on a similar case of TX, this makes code inconsistent.
Let's switch to either a error message or just a warning in both places.

2019-06-10 11:08:40

by Bitan Biswas

[permalink] [raw]
Subject: Re: [PATCH V3 6/6] i2c: tegra: remove BUG, BUG_ON



On 6/10/19 3:30 AM, Dmitry Osipenko wrote:
> 10.06.2019 8:08, 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 <[email protected]>
>> ---
>> drivers/i2c/busses/i2c-tegra.c | 18 +++++++++++-------
>> 1 file changed, 11 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>> index 4dfb4c1..d9e99b4 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 +877,10 @@ 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;
>>
>
> It looks nearly ideal now, although there is still one thing that could
> be improved. We're going to print a error message in a case of RX and
> spew a warning on a similar case of TX, this makes code inconsistent.
> Let's switch to either a error message or just a warning in both places.
>
Agree. I shall share the updated patch.

-Thanks,
Bitan