[PATCH v2] dmaengine: imx-sdma: remove BD_INTR for channel0

yibin.gong at nxp.com yibin.gong at nxp.com
Fri Jun 21 01:23:06 PDT 2019


From: Robin Gong <yibin.gong at nxp.com>

It is possible for an irq triggered by channel0 to be received later
after clks are disabled once firmware loaded during sdma probe. If
that happens then clearing them by writing to SDMA_H_INTR won't work
and the kernel will hang processing infinite interrupts. Actually,
don't need interrupt triggered on channel0 since it's pollling
SDMA_H_STATSTOP to know channel0 done rather than interrupt in
current code, just clear BD_INTR to disable channel0 interrupt to
avoid the above case.
This issue was brought by commit 1d069bfa3c78 ("dmaengine: imx-sdma:
ack channel 0 IRQ in the interrupt handler") which didn't take care
the above case.

Fixes: 1d069bfa3c78 ("dmaengine: imx-sdma: ack channel 0 IRQ in the interrupt handler")
Cc: stable at vger.kernel.org #5.0+
Signed-off-by: Robin Gong <yibin.gong at nxp.com>
Reported-by: Sven Van Asbroeck <thesven73 at gmail.com>
Tested-by: Sven Van Asbroeck <thesven73 at gmail.com>
---
 drivers/dma/imx-sdma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index deea9aa..b5a1ee2 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -742,7 +742,7 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
 	spin_lock_irqsave(&sdma->channel_0_lock, flags);
 
 	bd0->mode.command = C0_SETPM;
-	bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
+	bd0->mode.status = BD_DONE | BD_WRAP | BD_EXTD;
 	bd0->mode.count = size / 2;
 	bd0->buffer_addr = buf_phys;
 	bd0->ext_buffer_addr = address;
@@ -1064,7 +1064,7 @@ static int sdma_load_context(struct sdma_channel *sdmac)
 	context->gReg[7] = sdmac->watermark_level;
 
 	bd0->mode.command = C0_SETDM;
-	bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
+	bd0->mode.status = BD_DONE | BD_WRAP | BD_EXTD;
 	bd0->mode.count = sizeof(*context) / 4;
 	bd0->buffer_addr = sdma->context_phys;
 	bd0->ext_buffer_addr = 2048 + (sizeof(*context) / 4) * channel;
-- 
2.7.4




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