Revision bb143f814ea488769ca2e79e0b376139cb5f134b authored by Vineet Gupta on 23 February 2016, 06:25:16 UTC, committed by Vineet Gupta on 24 February 2016, 05:37:28 UTC
ARConnect/MCIP Inter-Core-Interrupt module can't send interrupt to local core. So use core intc capability to trigger software interrupt to self, using an unsued IRQ #21. This showed up as csd deadlock with LTP trace_sched on a dual core system. This test acts as scheduler fuzzer, triggering all sorts of schedulting activity. Trouble starts with IPI to self, which doesn't get delivered (effectively lost due to H/w capability), but the msg intended to be sent remain enqueued in per-cpu @ipi_data. All subsequent IPIs to this core from other cores get elided due to the IPI coalescing optimization in ipi_send_msg_one() where a pending msg implies an IPI already sent and assumes other core is yet to ack it. After the elided IPI, other core simply goes into csd_lock_wait() but never comes out as this core never sees the interrupt. Fixes STAR 9001008624 Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> [4.2] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
1 parent 3e5177c
File | Mode | Size |
---|---|---|
hci | ||
nci | ||
Kconfig | -rw-r--r-- | 805 bytes |
Makefile | -rw-r--r-- | 339 bytes |
af_nfc.c | -rw-r--r-- | 2.4 KB |
core.c | -rw-r--r-- | 24.8 KB |
digital.h | -rw-r--r-- | 5.6 KB |
digital_core.c | -rw-r--r-- | 19.9 KB |
digital_dep.c | -rw-r--r-- | 32.4 KB |
digital_technology.c | -rw-r--r-- | 27.1 KB |
llcp.h | -rw-r--r-- | 7.3 KB |
llcp_commands.c | -rw-r--r-- | 16.5 KB |
llcp_core.c | -rw-r--r-- | 34.6 KB |
llcp_sock.c | -rw-r--r-- | 22.1 KB |
netlink.c | -rw-r--r-- | 38.8 KB |
nfc.h | -rw-r--r-- | 5.0 KB |
rawsock.c | -rw-r--r-- | 9.6 KB |
Computing file changes ...