diff mbox series

[net-next,4/8] igc: recalculate Qbv end_time by considering cycle time

Message ID 20221205212414.3197525-5-anthony.l.nguyen@intel.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series Intel Wired LAN Driver Updates 2022-12-05 (igc) | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -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: 0 this patch: 0
netdev/cc_maintainers success CCed 5 of 5 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 No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 21 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Tony Nguyen Dec. 5, 2022, 9:24 p.m. UTC 
From: Tan Tee Min <tee.min.tan@linux.intel.com>

Qbv users can specify a cycle time that is not equal to the total GCL
intervals. Hence, recalculation is necessary here to exclude the time
interval that exceeds the cycle time. As those GCL which exceeds the
cycle time will be truncated.

According to IEEE Std. 802.1Q-2018 section 8.6.9.2, once the end of
the list is reached, it will switch to the END_OF_CYCLE state and
leave the gates in the same state until the next cycle is started.

Signed-off-by: Tan Tee Min <tee.min.tan@linux.intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
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 35c473703950..5aa72eac2a35 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -5952,6 +5952,21 @@  static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 
 		end_time += e->interval;
 
+		/* If any of the conditions below are true, we need to manually
+		 * control the end time of the cycle.
+		 * 1. Qbv users can specify a cycle time that is not equal
+		 * to the total GCL intervals. Hence, recalculation is
+		 * necessary here to exclude the time interval that
+		 * exceeds the cycle time.
+		 * 2. According to IEEE Std. 802.1Q-2018 section 8.6.9.2,
+		 * once the end of the list is reached, it will switch
+		 * to the END_OF_CYCLE state and leave the gates in the
+		 * same state until the next cycle is started.
+		 */
+		if (end_time > adapter->cycle_time ||
+		    n + 1 == qopt->num_entries)
+			end_time = adapter->cycle_time;
+
 		for (i = 0; i < adapter->num_tx_queues; i++) {
 			struct igc_ring *ring = adapter->tx_ring[i];