kgdb,8250,pl011: Return immediately from console poll
authorJason Wessel <jason.wessel@windriver.com>
Fri, 21 May 2010 02:04:22 +0000 (21:04 -0500)
committerJason Wessel <jason.wessel@windriver.com>
Fri, 21 May 2010 02:04:22 +0000 (21:04 -0500)
commitf5316b4aea024da9266d740322a5481657f6ce59
tree5888fd0afa54fc3bab2711e583147c4b563836bc
parentdcc7871128e99458ca86186b7bc8bf27ff0c47b5
kgdb,8250,pl011: Return immediately from console poll

The design of the kdb shell requires that every device that can
provide input to kdb have a polling routine that exits immediately if
there is no character available.  This is required in order to get the
page scrolling mechanism working.

Changing the kernel debugger I/O API to require all polling character
routines to exit immediately if there is no data allows the kernel
debugger to process multiple input channels.

NO_POLL_CHAR will be the return code to the polling routine when ever
there is no character available.

CC: linux-serial@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
drivers/serial/8250.c
drivers/serial/amba-pl011.c
include/linux/kdb.h
include/linux/serial_core.h
kernel/debug/debug_core.c
kernel/debug/gdbstub.c
kernel/debug/kdb/kdb_debugger.c