From 7bf4a5b071e59f48de8d39dfde07a3a65e7f6488 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 15 Apr 2023 20:05:47 +0300 Subject: net: mscc: ocelot: optimize ocelot_mm_irq() The MAC Merge IRQ of all ports is shared with the PTP TX timestamp IRQ of all ports, which means that currently, when a PTP TX timestamp is generated, felix_irq_handler() also polls for the MAC Merge layer status of all ports, looking for changes. This makes the kernel do more work, and under certain circumstances may make ptp4l require a tx_timestamp_timeout argument higher than before. Changes to the MAC Merge layer status are only to be expected under certain conditions - its TX direction needs to be enabled - so we can check early if that is the case, and omit register access otherwise. Make ocelot_mm_update_port_status() skip register access if mm->tx_enabled is unset, and also call it once more, outside IRQ context, from ocelot_port_set_mm(), when mm->tx_enabled transitions from true to false, because an IRQ is also expected in that case. Also, a port may have its MAC Merge layer enabled but it may not have generated the interrupt. In that case, there's no point in writing to DEV_MM_STATUS to acknowledge that IRQ. We can reduce the number of register writes per port with MM enabled by keeping an "ack" variable which writes the "write-one-to-clear" bits. Those are 3 in number: PRMPT_ACTIVE_STICKY, UNEXP_RX_PFRM_STICKY and UNEXP_TX_PFRM_STICKY. The other fields in DEV_MM_STATUS are read-only and it doesn't matter what is written to them, so writing zero is just fine. Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski --- include/soc/mscc/ocelot.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/soc') diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index 9599be6a0a39..ee8d43dc5c06 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -745,6 +745,7 @@ struct ocelot_mirror { struct ocelot_mm_state { enum ethtool_mm_verify_status verify_status; + bool tx_enabled; bool tx_active; }; -- cgit v1.2.3-58-ga151