diff mbox series

[V2,01/12,net-next] qca_spi: Improve SPI thread creation

Message ID 20231218232639.33327-2-wahrenst@gmx.net (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series qca_spi: collection of improvements | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
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: 1115 this patch: 1115
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang fail Errors and warnings before: 12 this patch: 12
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 No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1142 this patch: 1142
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 76 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

Commit Message

Stefan Wahren Dec. 18, 2023, 11:26 p.m. UTC 
The qca_spi driver create/stop the SPI kernel thread in case
of netdev_open/close. This isn't optimal because there is no
need for such an expensive operation.

So improve this by moving create/stop of the SPI kernel into
the init/uninit ops. The open/close ops could just
'park/unpark' the SPI kernel thread.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 drivers/net/ethernet/qualcomm/qca_spi.c | 33 ++++++++++++++-----------
 1 file changed, 18 insertions(+), 15 deletions(-)

--
2.34.1

Comments

Jacob Keller Dec. 20, 2023, 11:05 p.m. UTC | #1 
On 12/18/2023 3:26 PM, Stefan Wahren wrote:
> The qca_spi driver create/stop the SPI kernel thread in case
> of netdev_open/close. This isn't optimal because there is no
> need for such an expensive operation.
> 
> So improve this by moving create/stop of the SPI kernel into
> the init/uninit ops. The open/close ops could just
> 'park/unpark' the SPI kernel thread.
> 

If I understand, this is also important because kthread_stop would
ultimately result in the task being destroyed and thus user space
configuration of the task (priority, pinning, etc) would be lost too.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 5f3c11fb3fa2..fc272ca7bdca 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -697,25 +697,17 @@  qcaspi_netdev_open(struct net_device *dev)
 	qca->sync = QCASPI_SYNC_UNKNOWN;
 	qcafrm_fsm_init_spi(&qca->frm_handle);

-	qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
-				      qca, "%s", dev->name);
-
-	if (IS_ERR(qca->spi_thread)) {
-		netdev_err(dev, "%s: unable to start kernel thread.\n",
-			   QCASPI_DRV_NAME);
-		return PTR_ERR(qca->spi_thread);
-	}
-
 	ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
 			  dev->name, qca);
 	if (ret) {
 		netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
 			   QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
-		kthread_stop(qca->spi_thread);
 		return ret;
 	}

 	/* SPI thread takes care of TX queue */
+	kthread_unpark(qca->spi_thread);
+	wake_up_process(qca->spi_thread);

 	return 0;
 }
@@ -725,15 +717,11 @@  qcaspi_netdev_close(struct net_device *dev)
 {
 	struct qcaspi *qca = netdev_priv(dev);

-	netif_stop_queue(dev);
+	kthread_park(qca->spi_thread);

 	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
 	free_irq(qca->spi_dev->irq, qca);

-	kthread_stop(qca->spi_thread);
-	qca->spi_thread = NULL;
-	qcaspi_flush_tx_ring(qca);
-
 	return 0;
 }

@@ -825,6 +813,7 @@  static int
 qcaspi_netdev_init(struct net_device *dev)
 {
 	struct qcaspi *qca = netdev_priv(dev);
+	struct task_struct *thread;

 	dev->mtu = QCAFRM_MAX_MTU;
 	dev->type = ARPHRD_ETHER;
@@ -848,6 +837,15 @@  qcaspi_netdev_init(struct net_device *dev)
 		return -ENOBUFS;
 	}

+	thread = kthread_create(qcaspi_spi_thread, qca, "%s", dev->name);
+	if (IS_ERR(thread)) {
+		netdev_err(dev, "%s: unable to start kernel thread.\n",
+			   QCASPI_DRV_NAME);
+		return PTR_ERR(thread);
+	}
+
+	qca->spi_thread = thread;
+
 	return 0;
 }

@@ -856,6 +854,11 @@  qcaspi_netdev_uninit(struct net_device *dev)
 {
 	struct qcaspi *qca = netdev_priv(dev);

+	if (qca->spi_thread) {
+		kthread_stop(qca->spi_thread);
+		qca->spi_thread = NULL;
+	}
+
 	kfree(qca->rx_buffer);
 	qca->buffer_size = 0;
 	dev_kfree_skb(qca->rx_skb);