[PATCH 0/3] i2c: stm32: cleanup & stop handling fix
This series corrects the handling of the stop condition and cleanup few bits in the driver stm32f7_i2c.c
Alain Volmat (3): i2c: stm32: fix comment and remove unused AUTOEND bit i2c: stm32: remove unused stop parameter in start & reload handling i2c: stm32: only send a STOP upon transfer completion
drivers/i2c/stm32f7_i2c.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)
Comment within stm32_i2c_message_start is misleading, indicating that AUTOEND bit is setted while it is actually cleared. Moreover, the bit is actually never setted so there is no need to clear it hence get rid of this bit clear and the bit macro as well.
Signed-off-by: Alain Volmat alain.volmat@foss.st.com --- drivers/i2c/stm32f7_i2c.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index bf2a6c9b4b..78d7156492 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -57,7 +57,6 @@ struct stm32_i2c_regs { #define STM32_I2C_CR1_PE BIT(0)
/* STM32 I2C control 2 */ -#define STM32_I2C_CR2_AUTOEND BIT(25) #define STM32_I2C_CR2_RELOAD BIT(24) #define STM32_I2C_CR2_NBYTES_MASK GENMASK(23, 16) #define STM32_I2C_CR2_NBYTES(n) ((n & 0xff) << 16) @@ -304,9 +303,8 @@ static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv, cr2 |= STM32_I2C_CR2_SADD7(msg->addr); }
- /* Set nb bytes to transfer and reload or autoend bits */ - cr2 &= ~(STM32_I2C_CR2_NBYTES_MASK | STM32_I2C_CR2_RELOAD | - STM32_I2C_CR2_AUTOEND); + /* Set nb bytes to transfer and reload (if needed) */ + cr2 &= ~(STM32_I2C_CR2_NBYTES_MASK | STM32_I2C_CR2_RELOAD); if (msg->len > STM32_I2C_MAX_LEN) { cr2 |= STM32_I2C_CR2_NBYTES(STM32_I2C_MAX_LEN); cr2 |= STM32_I2C_CR2_RELOAD;
Hi,
On 9/8/22 10:06, Alain Volmat wrote:
Comment within stm32_i2c_message_start is misleading, indicating that AUTOEND bit is setted while it is actually cleared. Moreover, the bit is actually never setted so there is no need to clear it hence get rid of this bit clear and the bit macro as well.
Signed-off-by: Alain Volmat alain.volmat@foss.st.com
drivers/i2c/stm32f7_i2c.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index bf2a6c9b4b..78d7156492 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -57,7 +57,6 @@ struct stm32_i2c_regs { #define STM32_I2C_CR1_PE BIT(0)
/* STM32 I2C control 2 */ -#define STM32_I2C_CR2_AUTOEND BIT(25) #define STM32_I2C_CR2_RELOAD BIT(24) #define STM32_I2C_CR2_NBYTES_MASK GENMASK(23, 16) #define STM32_I2C_CR2_NBYTES(n) ((n & 0xff) << 16) @@ -304,9 +303,8 @@ static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv, cr2 |= STM32_I2C_CR2_SADD7(msg->addr); }
- /* Set nb bytes to transfer and reload or autoend bits */
- cr2 &= ~(STM32_I2C_CR2_NBYTES_MASK | STM32_I2C_CR2_RELOAD |
STM32_I2C_CR2_AUTOEND);
- /* Set nb bytes to transfer and reload (if needed) */
- cr2 &= ~(STM32_I2C_CR2_NBYTES_MASK | STM32_I2C_CR2_RELOAD); if (msg->len > STM32_I2C_MAX_LEN) { cr2 |= STM32_I2C_CR2_NBYTES(STM32_I2C_MAX_LEN); cr2 |= STM32_I2C_CR2_RELOAD;
Reviewed-by: Patrick Delaunay patrick.delaunay@foss.st.com
Thanks Patrick
Functions stm32_i2c_message_start and stm32_i2c_handle_reload both get a stop boolean indicating if the transfer should end with a STOP or not. However no specific handling is needed in those functions hence remove the parameter.
Signed-off-by: Alain Volmat alain.volmat@foss.st.com --- drivers/i2c/stm32f7_i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 78d7156492..0ec67b5c12 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -282,7 +282,7 @@ static int stm32_i2c_check_device_busy(struct stm32_i2c_priv *i2c_priv) }
static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv, - struct i2c_msg *msg, bool stop) + struct i2c_msg *msg) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 cr2 = readl(®s->cr2); @@ -325,7 +325,7 @@ static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv, */
static void stm32_i2c_handle_reload(struct stm32_i2c_priv *i2c_priv, - struct i2c_msg *msg, bool stop) + struct i2c_msg *msg) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 cr2 = readl(®s->cr2); @@ -431,7 +431,7 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, /* Add errors */ mask |= STM32_I2C_ISR_ERRORS;
- stm32_i2c_message_start(i2c_priv, msg, stop); + stm32_i2c_message_start(i2c_priv, msg);
while (msg->len) { /* @@ -469,7 +469,7 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, mask = msg->flags & I2C_M_RD ? STM32_I2C_ISR_RXNE : STM32_I2C_ISR_TXIS | STM32_I2C_ISR_NACKF;
- stm32_i2c_handle_reload(i2c_priv, msg, stop); + stm32_i2c_handle_reload(i2c_priv, msg); } else if (!bytes_to_rw) { /* Wait until TC flag is set */ mask = STM32_I2C_ISR_TC;
Hi
On 9/8/22 10:06, Alain Volmat wrote:
Functions stm32_i2c_message_start and stm32_i2c_handle_reload both get a stop boolean indicating if the transfer should end with a STOP or not. However no specific handling is needed in those functions hence remove the parameter.
Signed-off-by: Alain Volmat alain.volmat@foss.st.com
drivers/i2c/stm32f7_i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 78d7156492..0ec67b5c12 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -282,7 +282,7 @@ static int stm32_i2c_check_device_busy(struct stm32_i2c_priv *i2c_priv) }
static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv,
struct i2c_msg *msg, bool stop)
struct i2c_msg *msg)@@ -325,7 +325,7 @@ static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv, */
static void stm32_i2c_handle_reload(struct stm32_i2c_priv *i2c_priv,
struct i2c_msg *msg, bool stop)
struct i2c_msg *msg)@@ -431,7 +431,7 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, /* Add errors */ mask |= STM32_I2C_ISR_ERRORS;
- stm32_i2c_message_start(i2c_priv, msg, stop);
stm32_i2c_message_start(i2c_priv, msg);
while (msg->len) { /*
@@ -469,7 +469,7 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, mask = msg->flags & I2C_M_RD ? STM32_I2C_ISR_RXNE : STM32_I2C_ISR_TXIS | STM32_I2C_ISR_NACKF;
stm32_i2c_handle_reload(i2c_priv, msg, stop);
stm32_i2c_handle_reload(i2c_priv, msg);
Reviewed-by: Patrick Delaunay patrick.delaunay@foss.st.com
Thanks Patrick
Current function stm32_i2c_message_xfer is sending a STOP whatever the result of the transaction is. This can cause issues such as making the bus busy since the controller itself is already sending automatically a STOP when a NACK is generated. This can be especially seen when the processing get slower (ex: enabling lots of debug messages), ending up send 2 STOP (one automatically by the controller and a 2nd one at the end of the stm32_i2c_message_xfer function).
Signed-off-by: Alain Volmat alain.volmat@foss.st.com --- drivers/i2c/stm32f7_i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 0ec67b5c12..8803979d3e 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -477,16 +477,16 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, if (ret) break;
+ /* End of transfer, send stop condition */ + mask = STM32_I2C_CR2_STOP; + setbits_le32(®s->cr2, mask); + if (!stop) /* Message sent, new message has to be sent */ return 0; } }
- /* End of transfer, send stop condition */ - mask = STM32_I2C_CR2_STOP; - setbits_le32(®s->cr2, mask); - return stm32_i2c_check_end_of_message(i2c_priv); }
On 08/09/22, Alain Volmat wrote:
Current function stm32_i2c_message_xfer is sending a STOP whatever the result of the transaction is. This can cause issues such as making the bus busy since the controller itself is already sending automatically a STOP when a NACK is generated. This can be especially seen when the processing get slower (ex: enabling lots of debug messages), ending up send 2 STOP (one automatically by the controller and a 2nd one at the end of the stm32_i2c_message_xfer function).
um I debugged this - took me a couple of days - and I proposed a fix that has just been massaged a little in this PR.
IMO the best thing to do is either adding me - or to be fair yourself since you invested almost zero time on it - as a co-author. The hard bit was to find the issue in the first place.
what do you think?
I'll try to find some time to test this.
Signed-off-by: Alain Volmat alain.volmat@foss.st.com
drivers/i2c/stm32f7_i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 0ec67b5c12..8803979d3e 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -477,16 +477,16 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, if (ret) break;
/* End of transfer, send stop condition */mask = STM32_I2C_CR2_STOP;setbits_le32(®s->cr2, mask);if (!stop) /* Message sent, new message has to be sent */ return 0;
- /* End of transfer, send stop condition */
- mask = STM32_I2C_CR2_STOP;
- setbits_le32(®s->cr2, mask);
- return stm32_i2c_check_end_of_message(i2c_priv);
}
-- 2.25.1
Hi Jorge,
On Thu, Sep 08, 2022 at 10:36:22AM +0200, Jorge Ramirez-Ortiz, Foundries wrote:
On 08/09/22, Alain Volmat wrote:
Current function stm32_i2c_message_xfer is sending a STOP whatever the result of the transaction is. This can cause issues such as making the bus busy since the controller itself is already sending automatically a STOP when a NACK is generated. This can be especially seen when the processing get slower (ex: enabling lots of debug messages), ending up send 2 STOP (one automatically by the controller and a 2nd one at the end of the stm32_i2c_message_xfer function).
um I debugged this - took me a couple of days - and I proposed a fix that has just been massaged a little in this PR.
IMO the best thing to do is either adding me - or to be fair yourself since you invested almost zero time on it - as a co-author. The hard bit was to find the issue in the first place.
what do you think?
I'm very sorry, it wasn't my intention at all but indeed I should have taken more care to highlight your work. Sorry about that. I'm going to push a v2 for the serie, highlighting that and putting your Signed-of first.
I'll try to find some time to test this.
Signed-off-by: Alain Volmat alain.volmat@foss.st.com
drivers/i2c/stm32f7_i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 0ec67b5c12..8803979d3e 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -477,16 +477,16 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, if (ret) break;
/* End of transfer, send stop condition */mask = STM32_I2C_CR2_STOP;setbits_le32(®s->cr2, mask);if (!stop) /* Message sent, new message has to be sent */ return 0;
- /* End of transfer, send stop condition */
- mask = STM32_I2C_CR2_STOP;
- setbits_le32(®s->cr2, mask);
- return stm32_i2c_check_end_of_message(i2c_priv);
}
-- 2.25.1
participants (3)
-
Alain Volmat -
Jorge Ramirez-Ortiz, Foundries -
Patrick DELAUNAY