Re: [PATCH 3/3] dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer
From: Ludovic Desroches <ludovic.desroches@microchip.com>
Date: 2019-02-05 12:35:27
Also in:
dmaengine, lkml
On Tue, Feb 05, 2019 at 12:03:43PM +0100, Nicolas Ferre wrote:
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>
quoted hunk ↗ jump to hunk
--- drivers/dma/at_xdmac.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index ec7a29d8e448..b558a23ffbc2 100644 --- 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.-- 2.17.1
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