[PATCH 4.9 101/102] dmaengine: imx-sdma: remove BD_INTR for channel0

Greg Kroah-Hartman
2019-07-08T15:23:10Z

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

commit 3f93a4f297961c12bb17aa16cb3a4d1291823cae upstream.

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@vger.kernel.org #5.0+
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reported-by: Sven Van Asbroeck <thesven73@gmail.com>
Tested-by: Sven Van Asbroeck <thesven73@gmail.com>
Reviewed-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/dma/imx-sdma.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -632,7 +632,7 @@ static int sdma_load_script(struct sdma_
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;
@@ -909,7 +909,7 @@ static int sdma_load_context(struct sdma
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;