dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer

The overflow error flag (ROI: Request Overflow Error) is only relevant
for the case when the channel handles a peripheral synchronized transfer.
Not in the case of memory to memory transfer where there is no hardware
request signal.

Remove the use of this interrupt source in such a case. It's based on
the first descriptor which holds the configuration for the whole
linked list transfer.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 1dd7eda..06cbe54 100644 (file)
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -308,6 +308,11 @@ static inline int at_xdmac_csize(u32 maxburst)
        return csize;
 };
 
+static inline bool at_xdmac_chan_is_peripheral_xfer(u32 cfg)
+{
+       return cfg & AT_XDMAC_CC_TYPE_PER_TRAN;
+}
+
 static inline u8 at_xdmac_get_dwidth(u32 cfg)
 {
        return (cfg & AT_XDMAC_CC_DWIDTH_MASK) >> AT_XDMAC_CC_DWIDTH_OFFSET;
@@ -389,7 +394,13 @@ static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan,
                 at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
 
        at_xdmac_chan_write(atchan, AT_XDMAC_CID, 0xffffffff);
-       reg = AT_XDMAC_CIE_RBEIE | AT_XDMAC_CIE_WBEIE | AT_XDMAC_CIE_ROIE;
+       reg = AT_XDMAC_CIE_RBEIE | AT_XDMAC_CIE_WBEIE;
+       /*
+        * Request Overflow Error is only for peripheral synchronized transfers
+        */
+       if (at_xdmac_chan_is_peripheral_xfer(first->lld.mbr_cfg))
+               reg |= AT_XDMAC_CIE_ROIE;
+
        /*
         * There is no end of list when doing cyclic dma, we need to get
         * an interrupt after each periods.