diff mbox series

[iwl-net,v2,1/2] igc: Fix missing time sync events

Message ID 20240220235712.241552-2-vinicius.gomes@intel.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series igc/igb: Fix missing time sync events | 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: 956 this patch: 956
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 973 this patch: 973
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: 973 this patch: 973
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 58 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-2024-02-21--12-00 (tests: 1454)

Commit Message

Vinicius Costa Gomes Feb. 20, 2024, 11:57 p.m. UTC 
Fix "double" clearing of interrupts, which can cause external events
or timestamps to be missed.

The IGC_TSIRC Time Sync Interrupt Cause register can be cleared in two
ways, by either reading it or by writing '1' into the specific cause
bit. This is documented in section 8.16.1.

The following flow was used:
 1. read IGC_TSIRC into 'tsicr';
 2. handle the interrupts present in 'tsirc' and mark them in 'ack';
 3. write 'ack' into IGC_TSICR;

As both (1) and (3) will clear the interrupt cause, if the same
interrupt happens again between (1) and (3) it will be ignored,
causing events to be missed.

Remove the extra clear in (3).

Fixes: 2c344ae24501 ("igc: Add support for TX timestamping")
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Tested-by: Kurt Kanzenbach <kurt@linutronix.de> # Intel i225
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

Comments

naamax.meir March 6, 2024, 8:38 a.m. UTC | #1 
On 2/21/2024 01:57, Vinicius Costa Gomes wrote:
> Fix "double" clearing of interrupts, which can cause external events
> or timestamps to be missed.
> 
> The IGC_TSIRC Time Sync Interrupt Cause register can be cleared in two
> ways, by either reading it or by writing '1' into the specific cause
> bit. This is documented in section 8.16.1.
> 
> The following flow was used:
>   1. read IGC_TSIRC into 'tsicr';
>   2. handle the interrupts present in 'tsirc' and mark them in 'ack';
>   3. write 'ack' into IGC_TSICR;
> 
> As both (1) and (3) will clear the interrupt cause, if the same
> interrupt happens again between (1) and (3) it will be ignored,
> causing events to be missed.
> 
> Remove the extra clear in (3).
> 
> Fixes: 2c344ae24501 ("igc: Add support for TX timestamping")
> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
> Tested-by: Kurt Kanzenbach <kurt@linutronix.de> # Intel i225
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
> ---
>   drivers/net/ethernet/intel/igc/igc_main.c | 12 +-----------
>   1 file changed, 1 insertion(+), 11 deletions(-)

Tested-by: Naama Meir <naamax.meir@linux.intel.com>
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 ba8d3fe186ae..39b6a8d64de3 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -5302,25 +5302,22 @@  igc_features_check(struct sk_buff *skb, struct net_device *dev,
 
 static void igc_tsync_interrupt(struct igc_adapter *adapter)
 {
-	u32 ack, tsauxc, sec, nsec, tsicr;
 	struct igc_hw *hw = &adapter->hw;
+	u32 tsauxc, sec, nsec, tsicr;
 	struct ptp_clock_event event;
 	struct timespec64 ts;
 
 	tsicr = rd32(IGC_TSICR);
-	ack = 0;
 
 	if (tsicr & IGC_TSICR_SYS_WRAP) {
 		event.type = PTP_CLOCK_PPS;
 		if (adapter->ptp_caps.pps)
 			ptp_clock_event(adapter->ptp_clock, &event);
-		ack |= IGC_TSICR_SYS_WRAP;
 	}
 
 	if (tsicr & IGC_TSICR_TXTS) {
 		/* retrieve hardware timestamp */
 		igc_ptp_tx_tstamp_event(adapter);
-		ack |= IGC_TSICR_TXTS;
 	}
 
 	if (tsicr & IGC_TSICR_TT0) {
@@ -5334,7 +5331,6 @@  static void igc_tsync_interrupt(struct igc_adapter *adapter)
 		wr32(IGC_TSAUXC, tsauxc);
 		adapter->perout[0].start = ts;
 		spin_unlock(&adapter->tmreg_lock);
-		ack |= IGC_TSICR_TT0;
 	}
 
 	if (tsicr & IGC_TSICR_TT1) {
@@ -5348,7 +5344,6 @@  static void igc_tsync_interrupt(struct igc_adapter *adapter)
 		wr32(IGC_TSAUXC, tsauxc);
 		adapter->perout[1].start = ts;
 		spin_unlock(&adapter->tmreg_lock);
-		ack |= IGC_TSICR_TT1;
 	}
 
 	if (tsicr & IGC_TSICR_AUTT0) {
@@ -5358,7 +5353,6 @@  static void igc_tsync_interrupt(struct igc_adapter *adapter)
 		event.index = 0;
 		event.timestamp = sec * NSEC_PER_SEC + nsec;
 		ptp_clock_event(adapter->ptp_clock, &event);
-		ack |= IGC_TSICR_AUTT0;
 	}
 
 	if (tsicr & IGC_TSICR_AUTT1) {
@@ -5368,11 +5362,7 @@  static void igc_tsync_interrupt(struct igc_adapter *adapter)
 		event.index = 1;
 		event.timestamp = sec * NSEC_PER_SEC + nsec;
 		ptp_clock_event(adapter->ptp_clock, &event);
-		ack |= IGC_TSICR_AUTT1;
 	}
-
-	/* acknowledge the interrupts */
-	wr32(IGC_TSICR, ack);
 }
 
 /**