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dmaengine: at_xdmac: fix bug about channel configuration

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When using descriptor view 2 or higher, we don't write the configuration
into AT_XDMAC_CC register because this configuration will be fetch from
the descriptor. Unfortunately, the PROT bit is not updated with this
method, we have to do it manually before enabling the channel.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Ludovic Desroches 2015-06-17 16:22:26 +02:00 committed by Vinod Koul
parent 5dd90e5b91
commit 20cadcb4df
1 changed files with 10 additions and 9 deletions
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19
drivers/dma/at_xdmac.c
View File

@ -359,18 +359,19 @@ static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan,
* descriptor view 2 since some fields of the configuration register
* depend on transfer size and src/dest addresses.
*/
if (at_xdmac_chan_is_cyclic(atchan)) {
if (at_xdmac_chan_is_cyclic(atchan))
reg = AT_XDMAC_CNDC_NDVIEW_NDV1;
at_xdmac_chan_write(atchan, AT_XDMAC_CC, first->lld.mbr_cfg);
} else if (first->lld.mbr_ubc & AT_XDMAC_MBR_UBC_NDV3) {
else if (first->lld.mbr_ubc & AT_XDMAC_MBR_UBC_NDV3)
reg = AT_XDMAC_CNDC_NDVIEW_NDV3;
} else {
/*
* No need to write AT_XDMAC_CC reg, it will be done when the
* descriptor is fecthed.
*/
else
reg = AT_XDMAC_CNDC_NDVIEW_NDV2;
}
/*
* Even if the register will be updated from the configuration in the
* descriptor when using view 2 or higher, the PROT bit won't be set
* properly. This bit can be modified only by using the channel
* configuration register.
*/
at_xdmac_chan_write(atchan, AT_XDMAC_CC, first->lld.mbr_cfg);
reg |= AT_XDMAC_CNDC_NDDUP
| AT_XDMAC_CNDC_NDSUP