From: John Villalovos <jvillalo@xxxxxxxxxx> It seems that currently ASYNC_FLAGS is one bit short of covering all the bits of the ASYNC user flags. In particular it does not cover the ASYNC_AUTOPROBE bit. ASYNCB_LAST_USER and ASYNCB_AUTOPROBE are both equal to 15. Therefore: ASYNC_AUTOPROBE = 1000 0000 0000 0000 ASYNC_FLAGS = 0111 1111 1111 1111 So ASYNC_FLAGS is not covering the ASYNC_AUTOPROBE bit. This patch fixes the issue and with the patch the values will be: ASYNC_AUTOPROBE = 1000 0000 0000 0000 ASYNC_FLAGS = 1111 1111 1111 1111 As a side note, doing a "git grep" I didn't find any use of ASYNC_AUTOPROBE or ASYNCB_AUTOPROBE in the kernel, besides this include file. Signed-off-by: John Villalovos <john.l.villalovos@xxxxxxxxx> Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> Cc: Greg KH <greg@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/serial.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN include/linux/serial.h~serial-fix-missing-bit-coverage-of-async_flags include/linux/serial.h --- a/include/linux/serial.h~serial-fix-missing-bit-coverage-of-async_flags +++ a/include/linux/serial.h @@ -151,7 +151,7 @@ struct serial_uart_config { #define ASYNC_BUGGY_UART (1U << ASYNCB_BUGGY_UART) #define ASYNC_AUTOPROBE (1U << ASYNCB_AUTOPROBE) -#define ASYNC_FLAGS ((1U << ASYNCB_LAST_USER) - 1) +#define ASYNC_FLAGS ((1U << (ASYNCB_LAST_USER + 1)) - 1) #define ASYNC_USR_MASK (ASYNC_SPD_HI|ASYNC_SPD_VHI| \ ASYNC_CALLOUT_NOHUP|ASYNC_SPD_SHI|ASYNC_LOW_LATENCY) #define ASYNC_SPD_CUST (ASYNC_SPD_HI|ASYNC_SPD_VHI) _ -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html