On Tue, Jul 30, 2024 at 12:39:45PM +0530, Abhishek Singh wrote: > 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)); You just crashed the machine completely, sorry, but no, properly handle the issue and clean up if you can detect it, do not break systems. greg k-h
