Re: [PATCH v3 13/13] mmc: mmci: Add Qcom specific pio_read function.

[Srinivas Kandagatla]

Sorry Stephen for late reply,
Some reason this mail was filtered in other folders.

On 24/05/14 00:28, Stephen Boyd wrote:
> On 05/23/14 05:53, srinivas.kandagatla@xxxxxxxxxx wrote:
> > @@ -1022,6 +1025,40 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
> >   	}
> >   }
> >
> > +static int mmci_qcom_pio_read(struct mmci_host *host, char *buffer,
> > +			unsigned int remain)
> > +{
> > +	u32 *ptr = (u32 *) buffer;
> > +	unsigned int count = 0;
> > +	unsigned int words, bytes;
> > +	unsigned int fsize = host->variant->fifosize;
> > +
> > +	words = remain >> 2;
> > +	bytes = remain % 4;
> > +	/* read full words followed by leftover bytes */
> > +	if (words) {
> > +		while (readl(host->base + MMCISTATUS) & MCI_RXDATAAVLBL) {
> > +			*ptr = readl(host->base + MMCIFIFO + (count % fsize));
>
> This doesn't look endianness agnostic. Shouldn't we use ioread32_rep()
> to read this fifo?
Is'nt readl endianess aware?

we can not use ioread32_rep because as we can not reliably know how many 
words we should read? FIFOCNT would have helped but its not advised to 
be use as per the datasheet.



Thanks,
srini
> > +			ptr++;
> > +			count += 4;
> > +			words--;
> > +			if (!words)
> > +				break;
> > +		}
> > +	}
> > +
> > +	if (unlikely(bytes)) {
> > +		unsigned char buf[4];
> > +		if (readl(host->base + MMCISTATUS) & MCI_RXDATAAVLBL) {
> > +			*buf = readl(host->base + MMCIFIFO + (count % fsize));
> > +			memcpy(ptr, buf, bytes);
> > +			count += bytes;
> > +		}
> > +	}
> > +
> > +	return count;
> > +}
> > +
> >   static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
> >   {
> >   	void __iomem *base = host->base;
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