diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index f18d1bde04397178dfd4a88f263c77546449c381..a1cb25e277b503007dd043e096c913b8b8437cef 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -12,6 +12,11 @@ * also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc. * The support for MPC8349 DMA contorller is also added. * + * This driver instructs the DMA controller to issue the PCI Read Multiple + * command for PCI read operations, instead of using the default PCI Read Line + * command. Please be aware that this setting may result in read pre-fetching + * on some platforms. + * * This is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -49,9 +54,10 @@ static void dma_init(struct fsl_dma_chan *fsl_chan) case FSL_DMA_IP_83XX: /* Set the channel to below modes: * EOTIE - End-of-transfer interrupt enable + * PRC_RM - PCI read multiple */ - DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EOTIE, - 32); + DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EOTIE + | FSL_DMA_MR_PRC_RM, 32); break; } diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h index 4f21a512d84852cf2074084ffc8f7035228a2fe7..dc7f26865797cc12ef6610296a83919107c5ad84 100644 --- a/drivers/dma/fsldma.h +++ b/drivers/dma/fsldma.h @@ -38,6 +38,7 @@ /* Special MR definition for MPC8349 */ #define FSL_DMA_MR_EOTIE 0x00000080 +#define FSL_DMA_MR_PRC_RM 0x00000800 #define FSL_DMA_SR_CH 0x00000020 #define FSL_DMA_SR_PE 0x00000010