Commit 8a949b07 authored Sep 02, 2014 by Peter Hurley Committed by Greg Kroah-Hartman Sep 08, 2014

serial: core: Document lock requirement for UPF_* flags updates



The flags field of struct uart_port can only be safely modified
if the port mutex is held; no other lock prevents concurrent
changes from corrupting the field.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 16020b98

include/linux/serial_core.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -152,6 +152,7 @@ struct uart_port {
		unsigned long sysrq; /* sysrq timeout */
		#endif

		/* flags must be updated while holding port mutex */
		upf_t flags;

		#define UPF_FOURPORT ((__force upf_t) (1 << 1))