The help text says it must be a power of 2, and the implementation does rely on that. Enforce it.
A violation gives a wall of text, but the last few lines should be reasonably obvious:
drivers/serial/serial-uclass.c:334:9: note: in expansion of macro ‘BUILD_BUG_ON_NOT_POWER_OF_2’ 334 | BUILD_BUG_ON_NOT_POWER_OF_2(CONFIG_SERIAL_RX_BUFFER_SIZE);
Signed-off-by: Rasmus Villemoes ravi@prevas.dk --- drivers/serial/serial-uclass.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c index 28d7a202afc..484f0f7d3e8 100644 --- a/drivers/serial/serial-uclass.c +++ b/drivers/serial/serial-uclass.c @@ -18,6 +18,7 @@ #include <dm/lists.h> #include <dm/device-internal.h> #include <dm/of_access.h> +#include <linux/build_bug.h> #include <linux/delay.h>
DECLARE_GLOBAL_DATA_PTR; @@ -330,6 +331,8 @@ static int _serial_tstc(struct udevice *dev) struct serial_dev_priv *upriv = dev_get_uclass_priv(dev); uint wr, avail;
+ BUILD_BUG_ON_NOT_POWER_OF_2(CONFIG_SERIAL_RX_BUFFER_SIZE); + /* Read all available chars into the RX buffer while there's room */ avail = CONFIG_SERIAL_RX_BUFFER_SIZE - (upriv->wr_ptr - upriv->rd_ptr); while (avail-- && __serial_tstc(dev)) {