From: Paul Mackerras It turns out that we are not handling the TABDLY bits of the termios c_oflag field correctly on PPC, PPC64 and Alpha. These three architectures have a value for XTABS that is different from the TAB3 value. POSIX specifies that setting the TABDLY field to TAB3 should result in tabs being expanded to spaces. In n_tty.c:opost() we check for O_TABDLY(tty) == XTABS, which is fine on most architectures because they have XTABS == TAB3. I think the right thing to do is just to change the definition of XTABS to be the same as TAB3 on these architectures. The patch below does this for PPC and PPC64 (and I suggest the Alpha maintainer should do the same). At the moment, applications using either the XTABS or TAB3 values won't get the expected behaviour. With this patch, apps that use TAB3 will get the expected behaviour. Apps that use XTABS will need to be recompiled (but note that the POSIX-specified name to use is TAB3 not XTABS). --- 25-akpm/include/asm-ppc/termbits.h | 2 +- 25-akpm/include/asm-ppc64/termbits.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff -puN include/asm-ppc64/termbits.h~ppc-termio-fix include/asm-ppc64/termbits.h --- 25/include/asm-ppc64/termbits.h~ppc-termio-fix 2004-05-09 16:25:25.636662056 -0700 +++ 25-akpm/include/asm-ppc64/termbits.h 2004-05-09 16:25:25.640661448 -0700 @@ -89,6 +89,7 @@ struct termios { #define TAB1 00002000 #define TAB2 00004000 #define TAB3 00006000 +#define XTABS 00006000 /* required by POSIX to == TAB3 */ #define CRDLY 00030000 #define CR0 00000000 #define CR1 00010000 @@ -103,7 +104,6 @@ struct termios { #define VTDLY 00200000 #define VT0 00000000 #define VT1 00200000 -#define XTABS 01000000 /* Hmm.. Linux/i386 considers this part of TABDLY.. */ /* c_cflag bit meaning */ #define CBAUD 0000377 diff -puN include/asm-ppc/termbits.h~ppc-termio-fix include/asm-ppc/termbits.h --- 25/include/asm-ppc/termbits.h~ppc-termio-fix 2004-05-09 16:25:25.637661904 -0700 +++ 25-akpm/include/asm-ppc/termbits.h 2004-05-09 16:25:25.640661448 -0700 @@ -81,6 +81,7 @@ struct termios { #define TAB1 00002000 #define TAB2 00004000 #define TAB3 00006000 +#define XTABS 00006000 /* required by POSIX to == TAB3 */ #define CRDLY 00030000 #define CR0 00000000 #define CR1 00010000 @@ -95,7 +96,6 @@ struct termios { #define VTDLY 00200000 #define VT0 00000000 #define VT1 00200000 -#define XTABS 01000000 /* Hmm.. Linux/i386 considers this part of TABDLY.. */ /* c_cflag bit meaning */ #define CBAUD 0000377 _