From 5192fa99f0d267eb7bd1c79e556430ea8911ae38 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Sun, 4 Mar 2018 13:50:24 +0100 Subject: [PATCH] ivshmem-net: Refactor and comment ivshm_net_state_change This should make the state transitioning logic clearer. Also avoid the harmless but redundant netif_carrier_on/ivshm_net_run in RUN state. Signed-off-by: Jan Kiszka (cherry picked from commit 8539efe70fbdf4a0bea75a97c1628fbb38b6590b) --- drivers/net/ivshmem-net.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) --- a/drivers/net/ivshmem-net.c +++ b/drivers/net/ivshmem-net.c @@ -575,14 +575,21 @@ static void ivshm_net_state_change(struc struct net_device *ndev = in->napi.dev; u32 rstate = readl(&in->ivshm_regs->rstate); - switch (in->lstate) { case IVSHM_NET_STATE_RESET: + /* + * Wait for the remote to leave READY/RUN before transitioning + * to INIT. + */ if (rstate < IVSHM_NET_STATE_READY) ivshm_net_set_state(in, IVSHM_NET_STATE_INIT); break; case IVSHM_NET_STATE_INIT: + /* + * Wait for the remote to leave RESET before performing the + * initialization and moving to READY. + */ if (rstate > IVSHM_NET_STATE_RESET) { ivshm_net_init_queues(ndev); ivshm_net_set_state(in, IVSHM_NET_STATE_READY); @@ -594,11 +601,21 @@ static void ivshm_net_state_change(struc break; case IVSHM_NET_STATE_READY: - case IVSHM_NET_STATE_RUN: + /* + * Link is up and we are running once the remote is in READY or + * RUN. + */ if (rstate >= IVSHM_NET_STATE_READY) { netif_carrier_on(ndev); ivshm_net_run(ndev); - } else if (rstate == IVSHM_NET_STATE_RESET) { + break; + } + /* fall through */ + case IVSHM_NET_STATE_RUN: + /* + * If the remote goes to RESET, we need to follow immediately. + */ + if (rstate == IVSHM_NET_STATE_RESET) { netif_carrier_off(ndev); ivshm_net_do_stop(ndev); }