diff options
Diffstat (limited to 'drivers/mmc/host/alcor.c')
| -rw-r--r-- | drivers/mmc/host/alcor.c | 59 |
1 files changed, 32 insertions, 27 deletions
diff --git a/drivers/mmc/host/alcor.c b/drivers/mmc/host/alcor.c index c712b7deb3a9..7c8f203f9a24 100644 --- a/drivers/mmc/host/alcor.c +++ b/drivers/mmc/host/alcor.c @@ -48,7 +48,6 @@ struct alcor_sdmmc_host { struct mmc_command *cmd; struct mmc_data *data; unsigned int dma_on:1; - unsigned int early_data:1; struct mutex cmd_mutex; @@ -144,8 +143,7 @@ static void alcor_data_set_dma(struct alcor_sdmmc_host *host) host->sg_count--; } -static void alcor_trigger_data_transfer(struct alcor_sdmmc_host *host, - bool early) +static void alcor_trigger_data_transfer(struct alcor_sdmmc_host *host) { struct alcor_pci_priv *priv = host->alcor_pci; struct mmc_data *data = host->data; @@ -155,13 +153,6 @@ static void alcor_trigger_data_transfer(struct alcor_sdmmc_host *host, ctrl |= AU6601_DATA_WRITE; if (data->host_cookie == COOKIE_MAPPED) { - if (host->early_data) { - host->early_data = false; - return; - } - - host->early_data = early; - alcor_data_set_dma(host); ctrl |= AU6601_DATA_DMA_MODE; host->dma_on = 1; @@ -231,6 +222,7 @@ static void alcor_prepare_sg_miter(struct alcor_sdmmc_host *host) static void alcor_prepare_data(struct alcor_sdmmc_host *host, struct mmc_command *cmd) { + struct alcor_pci_priv *priv = host->alcor_pci; struct mmc_data *data = cmd->data; if (!data) @@ -248,7 +240,7 @@ static void alcor_prepare_data(struct alcor_sdmmc_host *host, if (data->host_cookie != COOKIE_MAPPED) alcor_prepare_sg_miter(host); - alcor_trigger_data_transfer(host, true); + alcor_write8(priv, 0, AU6601_DATA_XFER_CTRL); } static void alcor_send_cmd(struct alcor_sdmmc_host *host, @@ -435,7 +427,7 @@ static int alcor_cmd_irq_done(struct alcor_sdmmc_host *host, u32 intmask) if (!host->data) return false; - alcor_trigger_data_transfer(host, false); + alcor_trigger_data_transfer(host); host->cmd = NULL; return true; } @@ -456,7 +448,7 @@ static void alcor_cmd_irq_thread(struct alcor_sdmmc_host *host, u32 intmask) if (!host->data) alcor_request_complete(host, 1); else - alcor_trigger_data_transfer(host, false); + alcor_trigger_data_transfer(host); host->cmd = NULL; } @@ -487,15 +479,9 @@ static int alcor_data_irq_done(struct alcor_sdmmc_host *host, u32 intmask) break; case AU6601_INT_READ_BUF_RDY: alcor_trf_block_pio(host, true); - if (!host->blocks) - break; - alcor_trigger_data_transfer(host, false); return 1; case AU6601_INT_WRITE_BUF_RDY: alcor_trf_block_pio(host, false); - if (!host->blocks) - break; - alcor_trigger_data_transfer(host, false); return 1; case AU6601_INT_DMA_END: if (!host->sg_count) @@ -508,8 +494,14 @@ static int alcor_data_irq_done(struct alcor_sdmmc_host *host, u32 intmask) break; } - if (intmask & AU6601_INT_DATA_END) - return 0; + if (intmask & AU6601_INT_DATA_END) { + if (!host->dma_on && host->blocks) { + alcor_trigger_data_transfer(host); + return 1; + } else { + return 0; + } + } return 1; } @@ -1044,14 +1036,27 @@ static void alcor_init_mmc(struct alcor_sdmmc_host *host) mmc->caps2 = MMC_CAP2_NO_SDIO; mmc->ops = &alcor_sdc_ops; - /* Hardware cannot do scatter lists */ + /* The hardware does DMA data transfer of 4096 bytes to/from a single + * buffer address. Scatterlists are not supported, but upon DMA + * completion (signalled via IRQ), the original vendor driver does + * then immediately set up another DMA transfer of the next 4096 + * bytes. + * + * This means that we need to handle the I/O in 4096 byte chunks. + * Lacking a way to limit the sglist entries to 4096 bytes, we instead + * impose that only one segment is provided, with maximum size 4096, + * which also happens to be the minimum size. This means that the + * single-entry sglist handled by this driver can be handed directly + * to the hardware, nice and simple. + * + * Unfortunately though, that means we only do 4096 bytes I/O per + * MMC command. A future improvement would be to make the driver + * accept sg lists and entries of any size, and simply iterate + * through them 4096 bytes at a time. + */ mmc->max_segs = AU6601_MAX_DMA_SEGMENTS; mmc->max_seg_size = AU6601_MAX_DMA_BLOCK_SIZE; - - mmc->max_blk_size = mmc->max_seg_size; - mmc->max_blk_count = mmc->max_segs; - - mmc->max_req_size = mmc->max_seg_size * mmc->max_segs; + mmc->max_req_size = mmc->max_seg_size; } static int alcor_pci_sdmmc_drv_probe(struct platform_device *pdev) |