The user process on ARM closes the device node while closing the session, triggers a remote call to terminate the PD running on the DSP. If the DSP is in an unstable state and cannot process the remote request from the HLOS, glink fails to deliver the kill request to the DSP, resulting in a timeout error. Currently, this error is ignored, and the session is closed, causing all the SMMU mappings associated with that specific PD to be removed. However, since the PD is still operational on the DSP, any attempt to access these SMMU mappings results in an SMMU fault, leading to a panic. As the SMMU mappings have already been removed, there is no available information on the DSP to determine the root cause of its unresponsiveness to remote calls. As the DSP is unresponsive to all process remote calls, use BUG_ON to prevent the removal of SMMU mappings and to properly identify the root cause of the DSP’s unresponsiveness to the remote calls. Signed-off-by: Abhishek Singh <quic_abhishes@xxxxxxxxxxx> --- drivers/misc/fastrpc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index 5204fda51da3..bac9c749564c 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -97,6 +97,7 @@ #define FASTRPC_RMID_INIT_CREATE_STATIC 8 #define FASTRPC_RMID_INIT_MEM_MAP 10 #define FASTRPC_RMID_INIT_MEM_UNMAP 11 +#define PROCESS_KILL_SC 0x01010000 /* Protection Domain(PD) ids */ #define ROOT_PD (0) @@ -1128,6 +1129,9 @@ static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx, fastrpc_context_get(ctx); ret = rpmsg_send(cctx->rpdev->ept, (void *)msg, sizeof(*msg)); + /* trigger panic if glink communication is broken and the message is for PD kill */ + BUG_ON((ret == -ETIMEDOUT) && (handle == FASTRPC_INIT_HANDLE) && + (ctx->sc == PROCESS_KILL_SC)); if (ret) fastrpc_context_put(ctx); -- 2.25.1
