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: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2011-02-04 09:19:46 +00:00
parent 613b152c63
commit c8afc9d59c
1 changed files with 18 additions and 6 deletions

View File

@ -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