On Tue, 17 Jan 2023 17:10:50 -0500 Tom Rini trini@konsulko.com wrote:
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 sjg@chromium.org Cc: Sergei Antonov saproj@gmail.com Cc: Quentin Schulz quentin.schulz@theobroma-systems.com Cc: Andre Przywara andre.przywara@arm.com Fixes: 9591b63531fa ("Convert CONFIG_SYS_NS16550_MEM32 et al to Kconfig") Signed-off-by: Tom Rini trini@konsulko.com
Thanks, that indeed fixes the issue for me, booted on LicheePi Nano and Pine64-LTS:
Reviewed-by: Andre Przywara andre.przywara@arm.com Tested-by: Andre Przywara andre.przywara@arm.com
Cheers, Andre
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)