Commit d7618e38 authored Sep 27, 2019 by Benjamin Poirier Committed by Greg Kroah-Hartman Oct 04, 2019

staging: qlge: Fix irq masking in INTx mode

Tracing the driver operation reveals that the INTR_EN_EN bit (per-queue
interrupt control) does not immediately prevent rx completion interrupts
when the device is operating in INTx mode. This leads to interrupts being
raised while napi is scheduled/running. Those interrupts are ignored by
qlge_isr() and falsely reported as IRQ_NONE thanks to the irq_cnt scheme.
This in turn can cause frames to loiter in the receive queue until a later
frame leads to another rx interrupt that will schedule napi.

Use the INTR_EN_EI bit (master interrupt control) instead.

Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Link: https://lore.kernel.org/r/20190927101210.23856-2-bpoirier@suse.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 40115bbc

drivers/staging/qlge/qlge_main.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -3366,6 +3366,7 @@ msi:
		}
		}
		qlge_irq_type = LEG_IRQ;
		set_bit(QL_LEGACY_ENABLED, &qdev->flags);
		netif_printk(qdev, ifup, KERN_DEBUG, qdev->ndev,
		"Running with legacy interrupts.\n");
		}
		@@ -3509,6 +3510,16 @@ static void ql_resolve_queues_to_irqs(struct ql_adapter *qdev)
		intr_context->intr_dis_mask =
		INTR_EN_TYPE_MASK \| INTR_EN_INTR_MASK \|
		INTR_EN_TYPE_DISABLE;
		if (test_bit(QL_LEGACY_ENABLED, &qdev->flags)) {
		/* Experience shows that when using INTx interrupts,
		* the device does not always auto-mask INTR_EN_EN.
		* Moreover, masking INTR_EN_EN manually does not
		* immediately prevent interrupt generation.
		*/
		intr_context->intr_en_mask \|= INTR_EN_EI << 16 \|
		INTR_EN_EI;
		intr_context->intr_dis_mask \|= INTR_EN_EI << 16;
		}
		intr_context->intr_read_mask =
		INTR_EN_TYPE_MASK \| INTR_EN_INTR_MASK \| INTR_EN_TYPE_READ;
		/*

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