diff mbox series

[net-next,2/2] net: stmmac: move to threaded IRQ

Message ID 20220203184031.1074008-2-yannick.vignon@oss.nxp.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series [net-next,1/2] net: napi: wake up ksoftirqd if needed after scheduling NAPI | expand

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netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
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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 warning 2 maintainers not CCed: linux-arm-kernel@lists.infradead.org linux-stm32@st-md-mailman.stormreply.com
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/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: Possible repeated word: 'in' WARNING: line length of 81 exceeds 80 columns WARNING: line length of 87 exceeds 80 columns
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netdev/source_inline success Was 0 now: 0

Commit Message

Yannick Vignon Feb. 3, 2022, 6:40 p.m. UTC 
From: Yannick Vignon <yannick.vignon@nxp.com>

When an IRQ is forced threaded (such as with PREEMPT_RT), execution of the
handler remains protected by local_bh_disable()/local_bh_enable() calls to
keep the semantics of the IRQ context and avoid deadlocks. However, this
also creates a contention point where a higher prio interrupt handler gets
blocked by a lower prio task already holding the lock. Even though priority
inheritance kicks in in such a case, the lower prio task can still execute
for an indefinite time.

Move the stmmac interrupts to be explicitly threaded, so that high priority
traffic can be processed without delay even if another piece of code was
already running with BH disabled.

Signed-off-by: Yannick Vignon <yannick.vignon@nxp.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 28 +++++++++----------
 1 file changed, 14 insertions(+), 14 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index bde76ea2deec..4bfc2cb89456 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3459,8 +3459,8 @@  static int stmmac_request_irq_multi_msi(struct net_device *dev)
 	/* For common interrupt */
 	int_name = priv->int_name_mac;
 	sprintf(int_name, "%s:%s", dev->name, "mac");
-	ret = request_irq(dev->irq, stmmac_mac_interrupt,
-			  0, int_name, dev);
+	ret = request_threaded_irq(dev->irq, NULL, stmmac_mac_interrupt,
+				   IRQF_ONESHOT, int_name, dev);
 	if (unlikely(ret < 0)) {
 		netdev_err(priv->dev,
 			   "%s: alloc mac MSI %d (error: %d)\n",
@@ -3475,9 +3475,9 @@  static int stmmac_request_irq_multi_msi(struct net_device *dev)
 	if (priv->wol_irq > 0 && priv->wol_irq != dev->irq) {
 		int_name = priv->int_name_wol;
 		sprintf(int_name, "%s:%s", dev->name, "wol");
-		ret = request_irq(priv->wol_irq,
-				  stmmac_mac_interrupt,
-				  0, int_name, dev);
+		ret = request_threaded_irq(priv->wol_irq,
+					   NULL, stmmac_mac_interrupt,
+					   IRQF_ONESHOT, int_name, dev);
 		if (unlikely(ret < 0)) {
 			netdev_err(priv->dev,
 				   "%s: alloc wol MSI %d (error: %d)\n",
@@ -3493,9 +3493,9 @@  static int stmmac_request_irq_multi_msi(struct net_device *dev)
 	if (priv->lpi_irq > 0 && priv->lpi_irq != dev->irq) {
 		int_name = priv->int_name_lpi;
 		sprintf(int_name, "%s:%s", dev->name, "lpi");
-		ret = request_irq(priv->lpi_irq,
-				  stmmac_mac_interrupt,
-				  0, int_name, dev);
+		ret = request_threaded_irq(priv->lpi_irq,
+					   NULL, stmmac_mac_interrupt,
+					   IRQF_ONESHOT, int_name, dev);
 		if (unlikely(ret < 0)) {
 			netdev_err(priv->dev,
 				   "%s: alloc lpi MSI %d (error: %d)\n",
@@ -3604,8 +3604,8 @@  static int stmmac_request_irq_single(struct net_device *dev)
 	enum request_irq_err irq_err;
 	int ret;
 
-	ret = request_irq(dev->irq, stmmac_interrupt,
-			  IRQF_SHARED, dev->name, dev);
+	ret = request_threaded_irq(dev->irq, NULL, stmmac_interrupt,
+				   IRQF_SHARED | IRQF_ONESHOT, dev->name, dev);
 	if (unlikely(ret < 0)) {
 		netdev_err(priv->dev,
 			   "%s: ERROR: allocating the IRQ %d (error: %d)\n",
@@ -3618,8 +3618,8 @@  static int stmmac_request_irq_single(struct net_device *dev)
 	 * is used for WoL
 	 */
 	if (priv->wol_irq > 0 && priv->wol_irq != dev->irq) {
-		ret = request_irq(priv->wol_irq, stmmac_interrupt,
-				  IRQF_SHARED, dev->name, dev);
+		ret = request_threaded_irq(priv->wol_irq, NULL, stmmac_interrupt,
+					   IRQF_SHARED | IRQF_ONESHOT, dev->name, dev);
 		if (unlikely(ret < 0)) {
 			netdev_err(priv->dev,
 				   "%s: ERROR: allocating the WoL IRQ %d (%d)\n",
@@ -3631,8 +3631,8 @@  static int stmmac_request_irq_single(struct net_device *dev)
 
 	/* Request the IRQ lines */
 	if (priv->lpi_irq > 0 && priv->lpi_irq != dev->irq) {
-		ret = request_irq(priv->lpi_irq, stmmac_interrupt,
-				  IRQF_SHARED, dev->name, dev);
+		ret = request_threaded_irq(priv->lpi_irq, NULL, stmmac_interrupt,
+					   IRQF_SHARED | IRQF_ONESHOT, dev->name, dev);
 		if (unlikely(ret < 0)) {
 			netdev_err(priv->dev,
 				   "%s: ERROR: allocating the LPI IRQ %d (%d)\n",