diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c index 692de47b16701dc7b9f75aefa657618a352149d5..783ae763f445229dfe2f4122dc90870f6680f6a2 100644 --- a/drivers/dma/dw-edma/dw-edma-v0-core.c +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c @@ -192,6 +192,7 @@ u32 dw_edma_v0_core_status_abort_int(struct dw_edma *dw, enum dw_edma_dir dir) static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk) { struct dw_edma_burst *child; + struct dw_edma_chan *chan = chunk->chan; struct dw_edma_v0_lli __iomem *lli; struct dw_edma_v0_llp __iomem *llp; u32 control = 0, i = 0; @@ -205,9 +206,11 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk) j = chunk->bursts_alloc; list_for_each_entry(child, &chunk->burst->list, list) { j--; - if (!j) - control |= (DW_EDMA_V0_LIE | DW_EDMA_V0_RIE); - + if (!j) { + control |= DW_EDMA_V0_LIE; + if (!(chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL)) + control |= DW_EDMA_V0_RIE; + } /* Channel control */ SET_LL(&lli[i].control, control); /* Transfer size */ @@ -233,6 +236,20 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk) SET_LL(&llp->llp_high, upper_32_bits(chunk->ll_region.paddr)); } +static void dw_edma_v0_sync_ll_data(struct dw_edma_chunk *chunk) +{ + /* + * In case of remote eDMA engine setup, the DW PCIe RP/EP internal + * configuration registers and application memory are normally accessed + * over different buses. Ensure LL-data reaches the memory before the + * doorbell register is toggled by issuing the dummy-read from the remote + * LL memory in a hope that the MRd TLP will return only after the + * last MWr TLP is completed + */ + if (!(chunk->chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL)) + readl(chunk->ll_region.vaddr.io); +} + void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first) { struct dw_edma_chan *chan = chunk->chan; @@ -262,6 +279,9 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first) SET_CH(dw, chan->dir, chan->id, llp_high, upper_32_bits(chunk->ll_region.paddr)); } + + dw_edma_v0_sync_ll_data(chunk); + /* Doorbell */ SET_RW(dw, chan->dir, doorbell, FIELD_PREP(EDMA_V0_DOORBELL_CH_MASK, chan->id)); diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h index cab6e18773dadd2149f6310e0c87316137419d24..0cda04f9f610f994946cfdcb86368f254c02cecf 100644 --- a/include/linux/dma/edma.h +++ b/include/linux/dma/edma.h @@ -14,17 +14,27 @@ struct dw_edma; +/** + * enum dw_edma_chip_flags - Flags specific to an eDMA chip + * @DW_EDMA_CHIP_LOCAL: eDMA is used locally by an endpoint + */ +enum dw_edma_chip_flags { + DW_EDMA_CHIP_LOCAL = BIT(0), +}; + /** * struct dw_edma_chip - representation of DesignWare eDMA controller hardware * @dev: struct device of the eDMA controller * @id: instance ID * @irq: irq line * @dw: struct dw_edma that is filed by dw_edma_probe() + * @flags dw_edma_chip_flags */ struct dw_edma_chip { struct device *dev; int id; int irq; + u32 flags; struct dw_edma *dw; };