flash: stm32l4/g4: force load option bytes after write

JordanYates · kartben · commit a5643a466426 · 2025-01-08T01:29:53.000+01:00
After writing option bytes, force them to be loaded. Failing to perform
this step means the values are never applied and not actually written
to non-volatile memory.

Signed-off-by: Jordan Yates &lt;jordan@embeint.com&gt;
diff --git a/drivers/flash/flash_stm32g4x.c b/drivers/flash/flash_stm32g4x.c
@@ -285,7 +285,10 @@ int flash_stm32_option_bytes_write(const struct device *dev, uint32_t mask,
 		return rc;
 	}
 
-	return 0;
+	/* Force the option byte loading */
+	regs->CR |= FLASH_CR_OBL_LAUNCH;
+
+	return flash_stm32_wait_flash_idle(dev);
 }
 
 uint32_t flash_stm32_option_bytes_read(const struct device *dev)
diff --git a/drivers/flash/flash_stm32l4x.c b/drivers/flash/flash_stm32l4x.c
@@ -276,7 +276,10 @@ int flash_stm32_option_bytes_write(const struct device *dev, uint32_t mask,
 		return rc;
 	}
 
-	return 0;
+	/* Force the option byte loading */
+	regs->CR |= FLASH_CR_OBL_LAUNCH;
+
+	return flash_stm32_wait_flash_idle(dev);
 }
 
 uint32_t flash_stm32_option_bytes_read(const struct device *dev)

Original file line number	Diff line number	Diff line change
`@@ -285,7 +285,10 @@ int flash_stm32_option_bytes_write(const struct device *dev, uint32_t mask,`
`285`	`285`	`return rc;`
`286`	`286`	`}`
`287`	`287`
`288`		`- return 0;`
	`288`	`+ /* Force the option byte loading */`
	`289`	`+ regs->CR \|= FLASH_CR_OBL_LAUNCH;`
	`290`	`+`
	`291`	`+ return flash_stm32_wait_flash_idle(dev);`
`289`	`292`	`}`
`290`	`293`
`291`	`294`	`uint32_t flash_stm32_option_bytes_read(const struct device *dev)`
Original file line number	Diff line number	Diff line change
`@@ -276,7 +276,10 @@ int flash_stm32_option_bytes_write(const struct device *dev, uint32_t mask,`
`276`	`276`	`return rc;`
`277`	`277`	`}`
`278`	`278`
`279`		`- return 0;`
	`279`	`+ /* Force the option byte loading */`
	`280`	`+ regs->CR \|= FLASH_CR_OBL_LAUNCH;`
	`281`	`+`
	`282`	`+ return flash_stm32_wait_flash_idle(dev);`
`280`	`283`	`}`
`281`	`284`
`282`	`285`	`uint32_t flash_stm32_option_bytes_read(const struct device *dev)`