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authorPeter Hurley <peter@hurleysoftware.com>2014-09-03 01:39:19 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-09-09 03:23:36 +0400
commit8a949b07e4062cbd07e04e6a47249e69ca65b944 (patch)
treefd8cfdd636e4bd27bcf6c3af31da41149d3139e4 /include/linux/serial_core.h
parent16020b989ac72b0b02654612a7b70398a7faac21 (diff)
downloadlinux-8a949b07e4062cbd07e04e6a47249e69ca65b944.tar.xz
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>
Diffstat (limited to 'include/linux/serial_core.h')
-rw-r--r--include/linux/serial_core.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index cf3a1e789bf5..8cb267b1fcd5 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -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))