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[net,5/8] net: mscc: ocelot: fix race between ndo_get_stats64 and ocelot_check_stats_work

Message ID 20220816135352.1431497-6-vladimir.oltean@nxp.com (mailing list archive)
State Accepted
Commit 18d8e67df184081bc6ce6220a2dd965cfd3d7e6b
Delegated to: Netdev Maintainers
Headers show
Series Fixes for Ocelot driver statistics | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 85 this patch: 85
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 85 this patch: 85
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Vladimir Oltean Aug. 16, 2022, 1:53 p.m. UTC
The 2 methods can run concurrently, and one will change the window of
counters (SYS_STAT_CFG_STAT_VIEW) that the other sees. The fix is
similar to what commit 7fbf6795d127 ("net: mscc: ocelot: fix mutex lock
error during ethtool stats read") has done for ethtool -S.

Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/net/ethernet/mscc/ocelot_net.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 9d8cea16245e..6b9d37138844 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -726,6 +726,8 @@  static void ocelot_get_stats64(struct net_device *dev,
 	struct ocelot *ocelot = priv->port.ocelot;
 	int port = priv->port.index;
 
+	spin_lock(&ocelot->stats_lock);
+
 	/* Configure the port to read the stats from */
 	ocelot_write(ocelot, SYS_STAT_CFG_STAT_VIEW(port),
 		     SYS_STAT_CFG);
@@ -758,6 +760,8 @@  static void ocelot_get_stats64(struct net_device *dev,
 	stats->tx_dropped = ocelot_read(ocelot, SYS_COUNT_TX_DROPS) +
 			    ocelot_read(ocelot, SYS_COUNT_TX_AGING);
 	stats->collisions = ocelot_read(ocelot, SYS_COUNT_TX_COLLISION);
+
+	spin_unlock(&ocelot->stats_lock);
 }
 
 static int ocelot_port_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],