Commit c8afc9d5 authored by Russell King's avatar Russell King
Browse files

ARM: mmci: avoid reporting too many completed bytes on fifo overrun 



The data counter counts the number of bytes transferred on the MMC bus.
When a FIFO overrun occurs, we will not have transferred a FIFOs-worth
of data to memory, and so the data counter will be a FIFOs-worth ahead.
If this occurs on a block boundary, we will report one too many sectors
as successful.  Fix this.

Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 613b152c

drivers/mmc/host/mmci.c

+18 −6
Original line number Diff line number Diff line
@@ -283,22 +283,34 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data, 
	if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {

		u32 remain, success;



		/* Calculate how far we are into the transfer */

		/*

		 * Calculate how far we are into the transfer.  Note that

		 * the data counter gives the number of bytes transferred

		 * on the MMC bus, not on the host side.  On reads, this

		 * can be as much as a FIFO-worth of data ahead.  This

		 * matters for FIFO overruns only.

		 */

		remain = readl(host->base + MMCIDATACNT);

		success = data->blksz * data->blocks - remain;



		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ (status %08x)\n", status);

		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ, status 0x%08x at 0x%08x\n",

			status, success);

		if (status & MCI_DATACRCFAIL) {

			/* Last block was not successful */

			host->data_xfered = round_down(success - 1, data->blksz);

			success -= 1;

			data->error = -EILSEQ;

		} else if (status & MCI_DATATIMEOUT) {

			host->data_xfered = round_down(success, data->blksz);

			data->error = -ETIMEDOUT;

		} else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN)) {

			host->data_xfered = round_down(success, data->blksz);

		} else if (status & MCI_TXUNDERRUN) {

			data->error = -EIO;

		} else if (status & MCI_RXOVERRUN) {

			if (success > host->variant->fifosize)

				success -= host->variant->fifosize;

			else

				success = 0;

			data->error = -EIO;

		}

		host->data_xfered = round_down(success, data->blksz);



		/*

		 * We hit an error condition.  Ensure that any data

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