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authorAlain Volmat <alain.volmat@foss.st.com>2022-09-12 10:42:00 +0200
committerPatrick Delaunay <patrick.delaunay@foss.st.com>2022-09-15 14:59:22 +0200
commit3bf699f7a8c650372b8d7e8ff4332a54e3a4fffa (patch)
treed3058a5554b7ce5e4e52de284186eba5d88da6ce
parentbcc7509265928895128c3a3b96087b9005ea6961 (diff)
i2c: stm32: do not set the STOP condition on error
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. Thanks to Jorge Ramirez-Ortiz for diagnosing and proposing a first fix for this. [1] [1] https://lore.kernel.org/u-boot/20220815145211.31342-2-jorge@foundries.io/ Reported-by: Jorge Ramirez-Ortiz, Foundries <jorge@foundries.io> Signed-off-by: Jorge Ramirez-Ortiz <jorge@foundries.io> Signed-off-by: Alain Volmat <alain.volmat@foss.st.com> Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> Reviewed-by: Heiko Schocher <hs@denx.de> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com> Tested-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
-rw-r--r--drivers/i2c/stm32f7_i2c.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c
index 8d680eea9b..80bd3c4caf 100644
--- a/drivers/i2c/stm32f7_i2c.c
+++ b/drivers/i2c/stm32f7_i2c.c
@@ -483,9 +483,9 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv,
}
}
- /* End of transfer, send stop condition */
- mask = STM32_I2C_CR2_STOP;
- setbits_le32(&regs->cr2, mask);
+ /* End of transfer, send stop condition if appropriate */
+ if (!ret && !(status & (STM32_I2C_ISR_NACKF | STM32_I2C_ISR_ERRORS)))
+ setbits_le32(&regs->cr2, STM32_I2C_CR2_STOP);
return stm32_i2c_check_end_of_message(i2c_priv);
}