linux-kernel - [RFC][PATCH 3/7] k3dma: Fix "nobody cared" message seen on any error

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Message-Id: <1468635207-20065-4-git-send-email-john.stultz@linaro.org>
Date:	Fri, 15 Jul 2016 19:13:23 -0700
From:	John Stultz <john.stultz@...aro.org>
To:	lkml <linux-kernel@...r.kernel.org>
Cc:	Andy Green <andy.green@...aro.org>,
	Zhangfei Gao <zhangfei.gao@...aro.org>,
	Jingoo Han <jg1.han@...sung.com>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	Maxime Ripard <maxime.ripard@...e-electrons.com>,
	Vinod Koul <vinod.koul@...el.com>,
	Dan Williams <dan.j.williams@...el.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>,
	Jaroslav Kysela <perex@...ex.cz>,
	Takashi Iwai <tiwai@...e.com>, Wei Xu <xuwei5@...ilicon.com>,
	Rob Herring <robh+dt@...nel.org>,
	Andy Green <andy@...mcat.com>,
	Dave Long <dave.long@...aro.org>,
	Guodong Xu <guodong.xu@...aro.org>,
	John Stultz <john.stultz@...aro.org>
Subject: [RFC][PATCH 3/7] k3dma: Fix "nobody cared" message seen on any error

From: Andy Green <andy.green@...aro.org>

As it was before, as soon as the DMAC IP felt there was an error
he would return IRQ_NONE since no actual transfer had completed.

After spinning on that for 100K interrupts, Linux yanks the IRQ with
a "nobody cared" error.

This patch lets it handle the interrupt and keep the IRQ alive.

Cc: Zhangfei Gao <zhangfei.gao@...aro.org>
Cc: Jingoo Han <jg1.han@...sung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@...sung.com>
Cc: Maxime Ripard <maxime.ripard@...e-electrons.com>
Cc: Vinod Koul <vinod.koul@...el.com>
Cc: Dan Williams <dan.j.williams@...el.com>
Cc: Liam Girdwood <lgirdwood@...il.com>
Cc: Mark Brown <broonie@...nel.org>
Cc: Jaroslav Kysela <perex@...ex.cz>
Cc: Takashi Iwai <tiwai@...e.com>
Cc: Wei Xu <xuwei5@...ilicon.com>
Cc: Rob Herring <robh+dt@...nel.org>
Cc: Andy Green <andy@...mcat.com>
Cc: Dave Long <dave.long@...aro.org>
Cc: Guodong Xu <guodong.xu@...aro.org>
Signed-off-by: Andy Green <andy.green@...aro.org>
[jstultz: Forward ported to mainline]
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
 drivers/dma/k3dma.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c
index 8dd050c..c2906a82 100644
--- a/drivers/dma/k3dma.c
+++ b/drivers/dma/k3dma.c
@@ -220,11 +220,13 @@ static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
 	writel_relaxed(err1, d->base + INT_ERR1_RAW);
 	writel_relaxed(err2, d->base + INT_ERR2_RAW);
 
-	if (irq_chan) {
+	if (irq_chan)
 		tasklet_schedule(&d->task);
+
+	if (irq_chan || err1 || err2)
 		return IRQ_HANDLED;
-	} else
-		return IRQ_NONE;
+
+	return IRQ_NONE;
 }
 
 static int k3_dma_start_txd(struct k3_dma_chan *c)
-- 
1.9.1