From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762802AbcINOOX (ORCPT ); Wed, 14 Sep 2016 10:14:23 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:35940 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751764AbcINOOV (ORCPT ); Wed, 14 Sep 2016 10:14:21 -0400 Date: Wed, 14 Sep 2016 16:14:14 +0200 From: Richard Cochran To: Grygorii Strashko Cc: "David S. Miller" , netdev@vger.kernel.org, Mugunthan V N , Sekhar Nori , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, WingMan Kwok Subject: Re: [PATCH 6/9] net: ethernet: ti: cpts: clean up event list if event pool is empty Message-ID: <20160914141414.GD28592@localhost.localdomain> References: <20160914130231.3035-1-grygorii.strashko@ti.com> <20160914130231.3035-7-grygorii.strashko@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160914130231.3035-7-grygorii.strashko@ti.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 14, 2016 at 04:02:28PM +0300, Grygorii Strashko wrote: > From: WingMan Kwok > > 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 > --- > drivers/net/ethernet/ti/cpts.c | 30 ++++++++++++++++++++++++++++-- > 1 file changed, 28 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c > index 970d4e2..ff8bb85 100644 > --- a/drivers/net/ethernet/ti/cpts.c > +++ b/drivers/net/ethernet/ti/cpts.c > @@ -57,22 +57,48 @@ static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low) > return -1; > } > > +static int cpts_event_list_clean_up(struct cpts *cpts) 5 words, that is quite a mouth full. How about this instead? 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; > + } > + } > + return removed; > +} > + > /* > * Returns zero if matching event type was found. > */ > static int cpts_fifo_read(struct cpts *cpts, int match) > { > int i, type = -1; > + int removed; No need for another variable, just change the return code above to return removed ? 0 : -1; and then you have ... > u32 hi, lo; > struct cpts_event *event; > > 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"); > - return -1; > + removed = cpts_event_list_clean_up(cpts); > + if (!removed) { > + dev_err(cpts->dev, > + "cpts: event pool is empty\n"); > + return -1; > + } if (cpts_purge_events(cpts)) { dev_err(cpts->dev, "cpts: event pool empty\n"); return -1; } Notice how I avoided the ugly line break? > + dev_dbg(cpts->dev, > + "cpts: event pool cleaned up %d\n", removed); > } > + > event = list_first_entry(&cpts->pool, struct cpts_event, list); > event->tmo = jiffies + 2; > event->high = hi; > -- > 2.9.3 > Thanks, Richard