diff options
Diffstat (limited to 'drivers/mmc/host/pxamci.c')
| -rw-r--r-- | drivers/mmc/host/pxamci.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/mmc/host/pxamci.c b/drivers/mmc/host/pxamci.c index 65210fca37e..d89475d3698 100644 --- a/drivers/mmc/host/pxamci.c +++ b/drivers/mmc/host/pxamci.c @@ -114,6 +114,7 @@ static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data) unsigned int nob = data->blocks; unsigned long long clks; unsigned int timeout; + bool dalgn = 0; u32 dcmd; int i; @@ -152,6 +153,9 @@ static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data) host->sg_cpu[i].dcmd = dcmd | length; if (length & 31 && !(data->flags & MMC_DATA_READ)) host->sg_cpu[i].dcmd |= DCMD_ENDIRQEN; + /* Not aligned to 8-byte boundary? */ + if (sg_dma_address(&data->sg[i]) & 0x7) + dalgn = 1; if (data->flags & MMC_DATA_READ) { host->sg_cpu[i].dsadr = host->res->start + MMC_RXFIFO; host->sg_cpu[i].dtadr = sg_dma_address(&data->sg[i]); @@ -165,6 +169,15 @@ static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data) host->sg_cpu[host->dma_len - 1].ddadr = DDADR_STOP; wmb(); + /* + * The PXA27x DMA controller encounters overhead when working with + * unaligned (to 8-byte boundaries) data, so switch on byte alignment + * mode only if we have unaligned data. + */ + if (dalgn) + DALGN |= (1 << host->dma); + else + DALGN &= (1 << host->dma); DDADR(host->dma) = host->sg_dma; DCSR(host->dma) = DCSR_RUN; } |