On 05/04/2012 12:24, Marek Vasut wrote:
> This SD DMA function of i.MX28 is still apparently too experimental to be
> enabled by default in 2012.04 release. Enable this feature only if the user
> plans to tinker with DCache or explicitly enables it.
>
> Signed-off-by: Marek Vasut <ma...@denx.de>
> Cc: Stefano Babic <sba...@denx.de>
> Cc: Wolfgang Denk <w...@denx.de>
> Cc: Detlev Zundel <d...@denx.de>
> Cc: Fabio Estevam <fabio.este...@freescale.com>
> ---
Hi Marek,
> drivers/mmc/mxsmmc.c | 41 ++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 40 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/mxsmmc.c b/drivers/mmc/mxsmmc.c
> index e8bad9d..7187796 100644
> --- a/drivers/mmc/mxsmmc.c
> +++ b/drivers/mmc/mxsmmc.c
> @@ -66,8 +66,13 @@ mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
> struct mmc_data *data)
> struct mx28_ssp_regs *ssp_regs = priv->regs;
> uint32_t reg;
> int timeout;
> - uint32_t data_count, cache_data_count;
> + uint32_t data_count;
> uint32_t ctrl0;
> +#ifndef CONFIG_MXS_MMC_DMA
> + uint32_t *data_ptr;
> +#else
> + uint32_t cache_data_count;
> +#endif
>
> debug("MMC%d: CMD%d\n", mmc->block_dev.dev, cmd->cmdidx);
>
> @@ -185,7 +190,9 @@ mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
> struct mmc_data *data)
> return 0;
>
> data_count = data->blocksize * data->blocks;
> + timeout = MXSMMC_MAX_TIMEOUT;
>
> +#ifdef CONFIG_MXS_MMC_DMA
> if (data_count % ARCH_DMA_MINALIGN)
> cache_data_count = roundup(data_count, ARCH_DMA_MINALIGN);
> else
> @@ -218,6 +225,38 @@ mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
> struct mmc_data *data)
> invalidate_dcache_range((uint32_t)priv->desc->cmd.address,
> (uint32_t)(priv->desc->cmd.address + cache_data_count));
> }
> +#else
> + if (data->flags & MMC_DATA_READ) {
> + data_ptr = (uint32_t *)data->dest;
> + while (data_count && --timeout) {
> + reg = readl(&ssp_regs->hw_ssp_status);
> + if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
> + *data_ptr++ = readl(&ssp_regs->hw_ssp_data);
> + data_count -= 4;
> + timeout = MXSMMC_MAX_TIMEOUT;
> + } else
> + udelay(1000);
> + }
> + } else {
> + data_ptr = (uint32_t *)data->src;
> + timeout *= 100;
> + while (data_count && --timeout) {
> + reg = readl(&ssp_regs->hw_ssp_status);
> + if (!(reg & SSP_STATUS_FIFO_FULL)) {
> + writel(*data_ptr++, &ssp_regs->hw_ssp_data);
> + data_count -= 4;
> + timeout = MXSMMC_MAX_TIMEOUT;
> + } else
> + udelay(1000);
> + }
> + }
Ok, I see. This patch reverts to the status before applying the DMA's patch.
I would only ask if it makes sense to leave DMA support on MMC when we
know that is buggy. Is it DMA support working for NAND ? If yes, it is
not possible to enable DMA for NAND and disable it for MMC, as both
driver use the same CONFIG_MXS_MMC_DMA.
Anyway, I am not saying we should introduce a new switch, but maybe we
should drop DMA support in msx_mmc for this release avoiding confusion.
The current status with DMA support can be re-enabled on a -next branch.
Any thoughts ?
Best regards,
Stefano Babic
--
=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sba...@denx.de
=====================================================================
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
