@@ -191,11 +191,23 @@ static int stmmac_enable(struct ptp_clock_info *ptp,
priv->systime_flags);
write_unlock_irqrestore(&priv->ptp_lock, flags);
break;
- case PTP_CLK_REQ_EXTTS:
+ case PTP_CLK_REQ_EXTTS: {
+ u8 channel;
+
mutex_lock(&priv->aux_ts_lock);
acr_value = readl(ptpaddr + PTP_ACR);
+ channel = ilog2(FIELD_GET(PTP_ACR_MASK, acr_value));
acr_value &= ~PTP_ACR_MASK;
+
if (on) {
+ if (FIELD_GET(PTP_ACR_MASK, acr_value)) {
+ netdev_err(priv->dev,
+ "Cannot enable auxiliary snapshot %d as auxiliary snapshot %d is already enabled",
+ rq->extts.index, channel);
+ mutex_unlock(&priv->aux_ts_lock);
+ return -EBUSY;
+ }
+
priv->plat->flags |= STMMAC_FLAG_EXT_SNAPSHOT_EN;
/* Enable External snapshot trigger */
@@ -213,6 +225,7 @@ static int stmmac_enable(struct ptp_clock_info *ptp,
!(acr_value & PTP_ACR_ATSFC),
10, 10000);
break;
+ }
default:
break;
Even though the hardware theoretically supports up to 4 simultaneous auxiliary snapshot capture channels, the stmmac driver does support only a single channel to be active at a time. Previously in case of a PTP_CLK_REQ_EXTTS request, previously active auxiliary snapshot capture channels were silently dropped and the new channel was activated. Instead of silently changing the state for all consumers, log an error and return -EBUSY if a channel is already in use in order to signal to userspace to disable the currently active channel before enabling another one. Signed-off-by: Johannes Zink <j.zink@pengutronix.de> --- drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)