Patchwork [02/13] KSZ8851-SNL: Fix receive interrupt problem.

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Submitter Ben Dooks
Date April 29, 2010, 11:16 p.m.
Message ID <20100429231739.628756349@fluff.org.uk>
Download mbox | patch
Permalink /patch/51396/
State Changes Requested
Delegated to: David Miller
Headers show

Comments

Ben Dooks - April 29, 2010, 11:16 p.m.
From: Tristram Ha <Tristram.Ha@micrel.com>

This fixes a receive problem of the ks8851 snl network driver.

Under heavy TCP traffic the device will stop operating correctly. First
the receive interrupt is not triggered anymore.  After then the driver
cannot retrieve the correct packets from the device.  A workaround for
this problem is to disable the transmit done interrupt.

Signed-off-by: Tristram Ha <Tristram.Ha@micrel.com>
[ben@simtec.co.uk: cleaned up header]
Signed-off-by: Ben Dooks <ben@simtec.co.uk>

---
---
 drivers/net/ks8851.c |   10 ++++++++++
 1 file changed, 10 insertions(+)


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Patch

Index: b/drivers/net/ks8851.c
===================================================================
--- a/drivers/net/ks8851.c	2010-04-28 23:24:20.737026841 +0900
+++ b/drivers/net/ks8851.c	2010-04-29 00:51:12.489525834 +0900
@@ -553,6 +553,13 @@  static void ks8851_irq_work(struct work_
 
 	mutex_lock(&ks->lock);
 
+	/*
+	 * Turn off hardware interrupt during receive processing.  This fixes
+	 * the receive problem under heavy TCP traffic while transmit done
+	 * is enabled.
+	 */
+	ks8851_wrreg16(ks, KS_IER, 0);
+
 	status = ks8851_rdreg16(ks, KS_ISR);
 
 	if (netif_msg_intr(ks))
@@ -610,6 +617,9 @@  static void ks8851_irq_work(struct work_
 		ks8851_wrreg16(ks, KS_RXCR1, rxc->rxcr1);
 	}
 
+	/* Re-enable hardware interrupt. */
+	ks8851_wrreg16(ks, KS_IER, ks->rc_ier);
+
 	mutex_unlock(&ks->lock);
 
 	enable_irq(ks->netdev->irq);