From 58bf4db695287c4bb2a5fc9fc12c78fdd4c36894 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Wed, 29 Jun 2022 21:30:07 +0300 Subject: [PATCH] net: dsa: felix: fix race between reading PSFP stats and port stats Both PSFP stats and the port stats read by ocelot_check_stats_work() are indirectly read through the same mechanism - write to STAT_CFG:STAT_VIEW, read from SYS:STAT:CNT[n]. It's just that for port stats, we write STAT_VIEW with the index of the port, and for PSFP stats, we write STAT_VIEW with the filter index. So if we allow them to run concurrently, ocelot_check_stats_work() may change the view from vsc9959_psfp_counters_get(), and vice versa. Fixes: 7d4b564d6add ("net: dsa: felix: support psfp filter on vsc9959") Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20220629183007.3808130-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- drivers/net/dsa/ocelot/felix_vsc9959.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index 570d0204..9c27b9b 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -1886,6 +1886,8 @@ static void vsc9959_psfp_sgi_table_del(struct ocelot *ocelot, static void vsc9959_psfp_counters_get(struct ocelot *ocelot, u32 index, struct felix_stream_filter_counters *counters) { + mutex_lock(&ocelot->stats_lock); + ocelot_rmw(ocelot, SYS_STAT_CFG_STAT_VIEW(index), SYS_STAT_CFG_STAT_VIEW_M, SYS_STAT_CFG); @@ -1900,6 +1902,8 @@ static void vsc9959_psfp_counters_get(struct ocelot *ocelot, u32 index, SYS_STAT_CFG_STAT_VIEW(index) | SYS_STAT_CFG_STAT_CLEAR_SHOT(0x10), SYS_STAT_CFG); + + mutex_unlock(&ocelot->stats_lock); } static int vsc9959_psfp_filter_add(struct ocelot *ocelot, int port, -- 2.7.4