msm: ipc: Serialize SMD XPRT CLOSE and OPEN events
When a remote subsystem resets, IPC Router's SMD XPRT Layer queues a CLOSE
event. When the concerned subsytem powers up and the channel is reopened,
SMD XPRT Layer queues a OPEN event. When the remote subsytem resets and
powers up quickly, the following race condition exists:
a) IPC Router is scheduled out while handling the CLOSE event, leaving a
stale XPRT
b) IPC Router's SMD XPRT Layer queues a OPEN event
c) IPC Router's SMD XPRT Layer reads a HELLO message, finds a stale
XPRT and queues a DATA event on the stale XPRT
This race condition causes a kernel panic.
Fix this race condition by not handling any other SMD XPRT event until
the CLOSE event is complete.
CRs-Fixed: 488331
Change-Id: I2283e163413d1896bd6842530b8a6a2b537e22de
Signed-off-by: Zaheerulla Meer <zmeer@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>
diff --git a/arch/arm/mach-msm/ipc_router.h b/arch/arm/mach-msm/ipc_router.h
index d56c0dd..6f6cf64 100644
--- a/arch/arm/mach-msm/ipc_router.h
+++ b/arch/arm/mach-msm/ipc_router.h
@@ -170,6 +170,7 @@
int (*write)(void *data, uint32_t len,
struct msm_ipc_router_xprt *xprt);
int (*close)(struct msm_ipc_router_xprt *xprt);
+ void (*sft_close_done)(struct msm_ipc_router_xprt *xprt);
};
extern struct completion msm_ipc_remote_router_up;