From: Nicolas Ferre <[email protected]> The use of DMA slave config operation requires that the burst size (aka chunk size) is specified through this interface. Modify atmel-mci slave driver to use this specification on its side.
Signed-off-by: Nicolas Ferre <[email protected]> Signed-off-by: Ludovic Desroches <[email protected]> --- Hi Chris, Sorry for this trouble, this patch should apply well on 3.5-rc1. Thanks Regards Ludovic drivers/mmc/host/atmel-mci-regs.h | 14 ++++++++++++++ drivers/mmc/host/atmel-mci.c | 8 +++++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h index 787aba1..ab56f7d 100644 --- a/drivers/mmc/host/atmel-mci-regs.h +++ b/drivers/mmc/host/atmel-mci-regs.h @@ -140,4 +140,18 @@ #define atmci_writel(port,reg,value) \ __raw_writel((value), (port)->regs + reg) +/* + * Fix sconfig's burst size according to atmel MCI. We need to convert them as: + * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3. + * + * This can be done by finding most significant bit set. + */ +static inline unsigned int atmci_convert_chksize(unsigned int maxburst) +{ + if (maxburst > 1) + return fls(maxburst) - 2; + else + return 0; +} + #endif /* __DRIVERS_MMC_ATMEL_MCI_H__ */ diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 420aca6..556d384 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -910,6 +910,7 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data) enum dma_data_direction direction; enum dma_transfer_direction slave_dirn; unsigned int sglen; + u32 maxburst; u32 iflags; data->error = -EINPROGRESS; @@ -943,17 +944,18 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data) if (!chan) return -ENODEV; - if (host->caps.has_dma) - atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(3) | ATMCI_DMAEN); - if (data->flags & MMC_DATA_READ) { direction = DMA_FROM_DEVICE; host->dma_conf.direction = slave_dirn = DMA_DEV_TO_MEM; + maxburst = atmci_convert_chksize(host->dma_conf.src_maxburst); } else { direction = DMA_TO_DEVICE; host->dma_conf.direction = slave_dirn = DMA_MEM_TO_DEV; + maxburst = atmci_convert_chksize(host->dma_conf.dst_maxburst); } + atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | ATMCI_DMAEN); + sglen = dma_map_sg(chan->device->dev, data->sg, data->sg_len, direction); -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
