Prior to commit 9591b63531fa ("Convert CONFIG_SYS_NS16550_MEM32 et al to
Kconfig") we had defined CONFIG_SYS_NS16550_REG_SIZE to -1 with
DM_SERIAL such that we would then have a size 0 character array. This
resulted in functionally no padding. The confusion on my part came from
dealing with the constraints around platforms that do not use DM_SERIAL
in SPL/TPL. After Andre Przywara reported that sunxi was broken, I've
re-read the code and comments again and thought on this harder. What we
want I believe is what this patch does now.If DM_SERIAL is defined for this stage, regardless of CONFIG_SYS_NS16550_REG_SIZE then we will dynamically handle reg shifts and 'struct ns16550' needs no padding (which is functionally what unsigned char foo[0] provides). This is the same case as NS16550_DYNAMIC and DEBUG_UART. Expand the existing comment here slightly. Otherwise, we will have CONFIG_SYS_NS16550_REG_SIZE set to a non-zero value, and handle padding within the struct. Cc: Simon Glass <[email protected]> Cc: Sergei Antonov <[email protected]> Cc: Quentin Schulz <[email protected]> Cc: Andre Przywara <[email protected]> Fixes: 9591b63531fa ("Convert CONFIG_SYS_NS16550_MEM32 et al to Kconfig") Signed-off-by: Tom Rini <[email protected]> --- include/ns16550.h | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/include/ns16550.h b/include/ns16550.h index 243226fc3d94..e7e68663d030 100644 --- a/include/ns16550.h +++ b/include/ns16550.h @@ -26,15 +26,13 @@ #include <linux/types.h> -#if CONFIG_IS_ENABLED(DM_SERIAL) && !defined(CONFIG_SYS_NS16550_REG_SIZE) +#if CONFIG_IS_ENABLED(DM_SERIAL) || defined(CONFIG_NS16550_DYNAMIC) || \ + defined(CONFIG_DEBUG_UART) /* * For driver model we always use one byte per register, and sort out the - * differences in the driver + * differences in the driver. In the case of CONFIG_NS16550_DYNAMIC we do + * similar, and CONFIG_DEBUG_UART is responsible for shifts in its own manner. */ -#define CONFIG_SYS_NS16550_REG_SIZE (-1) -#endif - -#if defined(CONFIG_NS16550_DYNAMIC) || defined(CONFIG_DEBUG_UART) #define UART_REG(x) unsigned char x #else #if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0) -- 2.25.1
