diff mbox series

[net,3/4] igc: Fix reset adapter logics when tx mode change

Message ID 20240807231329.3827092-4-anthony.l.nguyen@intel.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series Intel Wired LAN Driver Updates 2024-08-07 (igc) | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 29 this patch: 29
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 29 this patch: 29
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: 29 this patch: 29
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-08-10--18-00 (tests: 707)

Commit Message

Tony Nguyen Aug. 7, 2024, 11:13 p.m. UTC 
From: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>

Following the "igc: Fix TX Hang issue when QBV Gate is close" changes,
remaining issues with the reset adapter logic in igc_tsn_offload_apply()
have been observed:

1. The reset adapter logics for i225 and i226 differ, although they should
   be the same according to the guidelines in I225/6 HW Design Section
   7.5.2.1 on software initialization during tx mode changes.
2. The i225 resets adapter every time, even though tx mode doesn't change.
   This occurs solely based on the condition  igc_is_device_id_i225() when
   calling schedule_work().
3. i226 doesn't reset adapter for tsn->legacy tx mode changes. It only
   resets adapter for legacy->tsn tx mode transitions.
4. qbv_count introduced in the patch is actually not needed; in this
   context, a non-zero value of qbv_count is used to indicate if tx mode
   was unconditionally set to tsn in igc_tsn_enable_offload(). This could
   be replaced by checking the existing register
   IGC_TQAVCTRL_TRANSMIT_MODE_TSN bit.

This patch resolves all issues and enters schedule_work() to reset the
adapter only when changing tx mode. It also removes reliance on qbv_count.

qbv_count field will be removed in a future patch.

Test ran:

1. Verify reset adapter behaviour in i225/6:
   a) Enrol a new GCL
      Reset adapter observed (tx mode change legacy->tsn)
   b) Enrol a new GCL without deleting qdisc
      No reset adapter observed (tx mode remain tsn->tsn)
   c) Delete qdisc
      Reset adapter observed (tx mode change tsn->legacy)

2. Tested scenario from "igc: Fix TX Hang issue when QBV Gate is closed"
   to confirm it remains resolved.

Fixes: 175c241288c0 ("igc: Fix TX Hang issue when QBV Gate is closed")
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_tsn.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 8ed7b965484d..ada751430517 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -49,6 +49,13 @@  static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
 	return new_flags;
 }
 
+static bool igc_tsn_is_tx_mode_in_tsn(struct igc_adapter *adapter)
+{
+	struct igc_hw *hw = &adapter->hw;
+
+	return !!(rd32(IGC_TQAVCTRL) & IGC_TQAVCTRL_TRANSMIT_MODE_TSN);
+}
+
 void igc_tsn_adjust_txtime_offset(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
@@ -365,15 +372,22 @@  int igc_tsn_reset(struct igc_adapter *adapter)
 	return err;
 }
 
-int igc_tsn_offload_apply(struct igc_adapter *adapter)
+static bool igc_tsn_will_tx_mode_change(struct igc_adapter *adapter)
 {
-	struct igc_hw *hw = &adapter->hw;
+	bool any_tsn_enabled = !!(igc_tsn_new_flags(adapter) &
+				  IGC_FLAG_TSN_ANY_ENABLED);
+
+	return (any_tsn_enabled && !igc_tsn_is_tx_mode_in_tsn(adapter)) ||
+	       (!any_tsn_enabled && igc_tsn_is_tx_mode_in_tsn(adapter));
+}
 
-	/* Per I225/6 HW Design Section 7.5.2.1, transmit mode
-	 * cannot be changed dynamically. Require reset the adapter.
+int igc_tsn_offload_apply(struct igc_adapter *adapter)
+{
+	/* Per I225/6 HW Design Section 7.5.2.1 guideline, if tx mode change
+	 * from legacy->tsn or tsn->legacy, then reset adapter is needed.
 	 */
 	if (netif_running(adapter->netdev) &&
-	    (igc_is_device_id_i225(hw) || !adapter->qbv_count)) {
+	    igc_tsn_will_tx_mode_change(adapter)) {
 		schedule_work(&adapter->reset_task);
 		return 0;
 	}