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

From: zhangfei
Date: Mon Jul 18 2016 - 02:40:53 EST




On 07/16/2016 10:13 AM, John Stultz wrote:
From: Andy Green <andy.green@xxxxxxxxxx>

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@xxxxxxxxxx>
Cc: Jingoo Han <jg1.han@xxxxxxxxxxx>
Cc: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Cc: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Liam Girdwood <lgirdwood@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Jaroslav Kysela <perex@xxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxxx>
Cc: Wei Xu <xuwei5@xxxxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Andy Green <andy@xxxxxxxxxxx>
Cc: Dave Long <dave.long@xxxxxxxxxx>
Cc: Guodong Xu <guodong.xu@xxxxxxxxxx>
Signed-off-by: Andy Green <andy.green@xxxxxxxxxx>
[jstultz: Forward ported to mainline]
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>

Acked-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>

---
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)