From f5316b4aea024da9266d740322a5481657f6ce59 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:22 -0500 Subject: 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 --- kernel/debug/debug_core.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 6e1fa829fdeb..1d71df66f3fa 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -882,6 +882,8 @@ EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); int dbg_io_get_char(void) { int ret = dbg_io_ops->read_char(); + if (ret == NO_POLL_CHAR) + return -1; if (!dbg_kdb_mode) return ret; if (ret == 127) -- cgit v1.2.3