[PATCH 4.2.y-ckt 163/268] dmaengine: at_xdmac: fix resume for cyclic transfers

From: Kamal Mostafa
Date: Wed Jan 27 2016 - 16:21:35 EST


4.2.8-ckt3 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Songjun Wu <songjun.wu@xxxxxxxxx>

commit 611dcadb01c89d1d3521450c05a4ded332e5a32d upstream.

When having cyclic transfers, the channel was paused when performing
suspend but was not correctly resumed.

Signed-off-by: Songjun Wu <songjun.wu@xxxxxxxxx>
Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel
eXtended DMA Controller driver")
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/dma/at_xdmac.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index c01cdec..756210a 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1524,6 +1524,7 @@ static int at_xdmac_device_terminate_all(struct dma_chan *chan)
list_for_each_entry_safe(desc, _desc, &atchan->xfers_list, xfer_node)
at_xdmac_remove_xfer(atchan, desc);

+ clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
clear_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status);
spin_unlock_irqrestore(&atchan->lock, flags);

@@ -1656,6 +1657,8 @@ static int atmel_xdmac_resume(struct device *dev)
atchan = to_at_xdmac_chan(chan);
at_xdmac_chan_write(atchan, AT_XDMAC_CC, atchan->save_cc);
if (at_xdmac_chan_is_cyclic(atchan)) {
+ if (at_xdmac_chan_is_paused(atchan))
+ at_xdmac_device_resume(chan);
at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, atchan->save_cnda);
at_xdmac_chan_write(atchan, AT_XDMAC_CNDC, atchan->save_cndc);
at_xdmac_chan_write(atchan, AT_XDMAC_CIE, atchan->save_cim);
--
1.9.1