From e4439fa838eb78b20f82665110b478018268833e Mon Sep 17 00:00:00 2001 From: WingMan Kwok Date: Tue, 6 Dec 2016 18:00:39 -0600 Subject: [PATCH] net: ethernet: ti: cpts: clean up event list if event pool is empty When a CPTS user does not exit gracefully by disabling cpts timestamping and leaving a joined multicast group, the system continues to receive and timestamps the ptp packets which eventually occupy all the event list entries. When this happns, the added code tries to remove some list entries which are expired. Signed-off-by: WingMan Kwok Signed-off-by: Grygorii Strashko Signed-off-by: David S. Miller --- drivers/net/ethernet/ti/cpts.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c index d3c1ac5e9336..7ab1fa73c0c0 100644 --- a/drivers/net/ethernet/ti/cpts.c +++ b/drivers/net/ethernet/ti/cpts.c @@ -57,6 +57,26 @@ static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low) return -1; } +static int cpts_purge_events(struct cpts *cpts) +{ + struct list_head *this, *next; + struct cpts_event *event; + int removed = 0; + + list_for_each_safe(this, next, &cpts->events) { + event = list_entry(this, struct cpts_event, list); + if (event_expired(event)) { + list_del_init(&event->list); + list_add(&event->list, &cpts->pool); + ++removed; + } + } + + if (removed) + pr_debug("cpts: event pool cleaned up %d\n", removed); + return removed ? 0 : -1; +} + /* * Returns zero if matching event type was found. */ @@ -69,10 +89,12 @@ static int cpts_fifo_read(struct cpts *cpts, int match) for (i = 0; i < CPTS_FIFO_DEPTH; i++) { if (cpts_fifo_pop(cpts, &hi, &lo)) break; - if (list_empty(&cpts->pool)) { - pr_err("cpts: event pool is empty\n"); + + if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) { + pr_err("cpts: event pool empty\n"); return -1; } + event = list_first_entry(&cpts->pool, struct cpts_event, list); event->tmo = jiffies + 2; event->high = hi; -- 2.20.1