diff --git a/drivers/mmc/host/pxamci.c b/drivers/mmc/host/pxamci.c index 3000422f4d81..9702ad3774cf 100644 --- a/drivers/mmc/host/pxamci.c +++ b/drivers/mmc/host/pxamci.c @@ -180,7 +180,15 @@ static void pxamci_setup_data(struct pxamci_host *host, struct mmc_data *data) else DALGN &= ~(1 << host->dma); DDADR(host->dma) = host->sg_dma; - DCSR(host->dma) = DCSR_RUN; + + /* + * workaround for erratum #91: + * only start DMA now if we are doing a read, + * otherwise we wait until CMD/RESP has finished + * before starting DMA. + */ + if (!cpu_is_pxa27x() || data->flags & MMC_DATA_READ) + DCSR(host->dma) = DCSR_RUN; } static void pxamci_start_cmd(struct pxamci_host *host, struct mmc_command *cmd, unsigned int cmdat) @@ -267,6 +275,12 @@ static int pxamci_cmd_done(struct pxamci_host *host, unsigned int stat) pxamci_disable_irq(host, END_CMD_RES); if (host->data && !cmd->error) { pxamci_enable_irq(host, DATA_TRAN_DONE); + /* + * workaround for erratum #91, if doing write + * enable DMA late + */ + if (cpu_is_pxa27x() && host->data->flags & MMC_DATA_WRITE) + DCSR(host->dma) = DCSR_RUN; } else { pxamci_finish_request(host, host->mrq); }