diff mbox series

[net-next,2/6] igc: Do not enable taprio offload for invalid arguments

Message ID 20230614140714.14443-3-florian.kauer@linutronix.de (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series igc: Fix corner cases for TSN offload | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 38 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Florian Kauer June 14, 2023, 2:07 p.m. UTC
Only set adapter->taprio_offload_enable after validating the arguments.
Otherwise, it stays set even if the offload was not enabled.
Since the subsequent code does not get executed in case of invalid
arguments, it will not be read at first.
However, by activating and then deactivating another offload
(e.g. ETF/TX launchtime offload), taprio_offload_enable is read
and erroneously keeps the offload feature of the NIC enabled.

This can be reproduced as follows:

    # TAPRIO offload (flags == 0x2) and negative base-time leading to expected -ERANGE
    sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24 taprio \
	    num_tc 1 \
	    map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
	    queues 1@0 \
	    base-time -1000 \
	    sched-entry S 01 300000 \
	    flags 0x2

    # IGC_TQAVCTRL is 0x0 as expected (iomem=relaxed for reading register)
    sudo pcimem /sys/bus/pci/devices/0000:01:00.0/resource0 0x3570 w*1

    # Activate ETF offload
    sudo tc qdisc replace dev enp1s0 parent root handle 6666 mqprio \
	    num_tc 3 \
	    map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
	    queues 1@0 1@1 2@2 \
	    hw 0
    sudo tc qdisc add dev enp1s0 parent 6666:1 etf \
	    clockid CLOCK_TAI \
	    delta 500000 \
	    offload

    # IGC_TQAVCTRL is 0x9 as expected
    sudo pcimem /sys/bus/pci/devices/0000:01:00.0/resource0 0x3570 w*1

    # Deactivate ETF offload again
    sudo tc qdisc delete dev enp1s0 parent 6666:1

    # IGC_TQAVCTRL should now be 0x0 again, but is observed as 0x9
    sudo pcimem /sys/bus/pci/devices/0000:01:00.0/resource0 0x3570 w*1

Fixes: e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")
Signed-off-by: Florian Kauer <florian.kauer@linutronix.de>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 56117846b8da..122158b321d5 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6091,6 +6091,7 @@  static int igc_tsn_clear_schedule(struct igc_adapter *adapter)
 
 	adapter->base_time = 0;
 	adapter->cycle_time = NSEC_PER_SEC;
+	adapter->taprio_offload_enable = false;
 	adapter->qbv_config_change_errors = 0;
 
 	for (i = 0; i < adapter->num_tx_queues; i++) {
@@ -6113,20 +6114,12 @@  static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 	size_t n;
 	int i;
 
-	switch (qopt->cmd) {
-	case TAPRIO_CMD_REPLACE:
-		adapter->taprio_offload_enable = true;
-		break;
-	case TAPRIO_CMD_DESTROY:
-		adapter->taprio_offload_enable = false;
-		break;
-	default:
-		return -EOPNOTSUPP;
-	}
-
-	if (!adapter->taprio_offload_enable)
+	if (qopt->cmd == TAPRIO_CMD_DESTROY)
 		return igc_tsn_clear_schedule(adapter);
 
+	if (qopt->cmd != TAPRIO_CMD_REPLACE)
+		return -EOPNOTSUPP;
+
 	if (qopt->base_time < 0)
 		return -ERANGE;
 
@@ -6138,6 +6131,7 @@  static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 
 	adapter->cycle_time = qopt->cycle_time;
 	adapter->base_time = qopt->base_time;
+	adapter->taprio_offload_enable = true;
 
 	for (n = 0; n < qopt->num_entries; n++) {
 		struct tc_taprio_sched_entry *e = &qopt->entries[n];