i2c: i2c-stm32f7: fix first byte to send in slave mode
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Message ID 1569857281-19419-1-git-send-email-fabrice.gasnier@st.com
State Accepted
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Series
  • i2c: i2c-stm32f7: fix first byte to send in slave mode
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Commit Message

Fabrice Gasnier Sept. 30, 2019, 3:28 p.m. UTC
The slave-interface documentation [1] states "the bus driver should
transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event:
- 'val': backend returns first byte to be sent
The driver currently ignores the 1st byte to send on this event.

Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")

[1] https://www.kernel.org/doc/Documentation/i2c/slave-interface

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
---
 drivers/i2c/busses/i2c-stm32f7.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Pierre Yves MORDRET Oct. 1, 2019, 7:10 a.m. UTC | #1
Hi,

Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>

Thx

On 9/30/19 5:28 PM, Fabrice Gasnier wrote:
> The slave-interface documentation [1] states "the bus driver should
> transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event:
> - 'val': backend returns first byte to be sent
> The driver currently ignores the 1st byte to send on this event.
> 
> Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
> 
> [1] https://www.kernel.org/doc/Documentation/i2c/slave-interface
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
> ---
>  drivers/i2c/busses/i2c-stm32f7.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index 266d1c2..0af9219 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -1192,6 +1192,8 @@ static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
>  			STM32F7_I2C_CR1_TXIE;
>  		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
>  
> +		/* Write 1st data byte */
> +		writel_relaxed(value, base + STM32F7_I2C_TXDR);
>  	} else {
>  		/* Notify i2c slave that new write transfer is starting */
>  		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
>
Fabrice Gasnier Oct. 15, 2019, 12:19 p.m. UTC | #2
On 9/30/19 5:28 PM, Fabrice Gasnier wrote:
> The slave-interface documentation [1] states "the bus driver should
> transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event:
> - 'val': backend returns first byte to be sent
> The driver currently ignores the 1st byte to send on this event.
> 
> Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
> 
> [1] https://www.kernel.org/doc/Documentation/i2c/slave-interface
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
> ---

Hi Wolfram, all,

Gentle reminder on this patch.

Thanks in advance !
Best Regards,
Fabrice

>  drivers/i2c/busses/i2c-stm32f7.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index 266d1c2..0af9219 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -1192,6 +1192,8 @@ static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
>  			STM32F7_I2C_CR1_TXIE;
>  		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
>  
> +		/* Write 1st data byte */
> +		writel_relaxed(value, base + STM32F7_I2C_TXDR);
>  	} else {
>  		/* Notify i2c slave that new write transfer is starting */
>  		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
>
Wolfram Sang Oct. 21, 2019, 2 p.m. UTC | #3
On Mon, Sep 30, 2019 at 05:28:01PM +0200, Fabrice Gasnier wrote:
> The slave-interface documentation [1] states "the bus driver should
> transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event:
> - 'val': backend returns first byte to be sent
> The driver currently ignores the 1st byte to send on this event.
> 
> Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
> 
> [1] https://www.kernel.org/doc/Documentation/i2c/slave-interface
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>

Applied to for-current, thanks!

Patch
diff mbox series

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 266d1c2..0af9219 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1192,6 +1192,8 @@  static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
 			STM32F7_I2C_CR1_TXIE;
 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
 
+		/* Write 1st data byte */
+		writel_relaxed(value, base + STM32F7_I2C_TXDR);
 	} else {
 		/* Notify i2c slave that new write transfer is starting */
 		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);