Re: [PATCH v2 1/7] mmc: mxs-mmc: add mmc host driver for i.MX23/28

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Mon, Feb 14, 2011 at 10:32:20AM +0800, Shawn Guo wrote:
> +	switch (mmc_resp_type(cmd)) {
> +	case MMC_RSP_NONE:
> +		break;
> +	case MMC_RSP_R1:
> +	case MMC_RSP_R1B:
> +	case MMC_RSP_R3:
> +		cmd->resp[0] = readl(host->base + HW_SSP_SDRESP0);
> +		break;
> +	case MMC_RSP_R2:
> +		cmd->resp[3] = readl(host->base + HW_SSP_SDRESP0);
> +		cmd->resp[2] = readl(host->base + HW_SSP_SDRESP1);
> +		cmd->resp[1] = readl(host->base + HW_SSP_SDRESP2);
> +		cmd->resp[0] = readl(host->base + HW_SSP_SDRESP3);

You really should be testing for MMC_RSP_PRESENT and MMC_RSP_136
here.  The response types are made up of a bitfield which allows
you to detect what's required rather than having to decode the
response type itself.

> +		else if (stat & BM_SSP_CTRL1_FIFO_UNDERRUN_IRQ)
> +			data->error = -ENODATA;
> +		else if (stat & BM_SSP_CTRL1_FIFO_OVERRUN_IRQ)
> +			data->error = -EOVERFLOW;

Both of these have a common error code - -EIO.