[PATCH 15/16] dmaengine: set_dma40: ignore spurious interrupts
Fabio Baltieri
fabio.baltieri at linaro.org
Mon Jan 7 06:21:57 EST 2013
Some DMA channels may be used by other cores in the SoC. This patch
modifies the dma interrupt handler to ignore interrupts from unknown
channels.
Cc: Rabin Vincent <rabin.vincent at stericsson.com>
Acked-by: Linus Walleij <linus.walleij at linaro.org>
Signed-off-by: Fabio Baltieri <fabio.baltieri at linaro.org>
---
drivers/dma/ste_dma40.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 2ecefb7..a97bbd3 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -1677,13 +1677,22 @@ static irqreturn_t d40_handle_interrupt(int irq, void *data)
row = chan / BITS_PER_LONG;
idx = chan & (BITS_PER_LONG - 1);
- /* ACK interrupt */
- writel(1 << idx, base->virtbase + il[row].clr);
-
if (il[row].offset == D40_PHY_CHAN)
d40c = base->lookup_phy_chans[idx];
else
d40c = base->lookup_log_chans[il[row].offset + idx];
+
+ if (!d40c) {
+ /*
+ * No error because this can happen if something else
+ * in the system is using the channel.
+ */
+ continue;
+ }
+
+ /* ACK interrupt */
+ writel(1 << idx, base->virtbase + il[row].clr);
+
spin_lock(&d40c->lock);
if (!il[row].is_error)
--
1.7.12.1
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