diff options
Diffstat (limited to 'drivers/mmc/host/mvsdio.c')
| -rw-r--r-- | drivers/mmc/host/mvsdio.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/mmc/host/mvsdio.c b/drivers/mmc/host/mvsdio.c index 9d3cfa9909c9..b56d72ff06e9 100644 --- a/drivers/mmc/host/mvsdio.c +++ b/drivers/mmc/host/mvsdio.c @@ -64,6 +64,31 @@ static int mvsd_setup_data(struct mvsd_host *host, struct mmc_data *data) unsigned int tmout; int tmout_index; + /* + * Hardware weirdness. The FIFO_EMPTY bit of the HW_STATE + * register is sometimes not set before a while when some + * "unusual" data block sizes are used (such as with the SWITCH + * command), even despite the fact that the XFER_DONE interrupt + * was raised. And if another data transfer starts before + * this bit comes to good sense (which eventually happens by + * itself) then the new transfer simply fails with a timeout. + */ + if (!(mvsd_read(MVSD_HW_STATE) & (1 << 13))) { + unsigned long t = jiffies + HZ; + unsigned int hw_state, count = 0; + do { + if (time_after(jiffies, t)) { + dev_warn(host->dev, "FIFO_EMPTY bit missing\n"); + break; + } + hw_state = mvsd_read(MVSD_HW_STATE); + count++; + } while (!(hw_state & (1 << 13))); + dev_dbg(host->dev, "*** wait for FIFO_EMPTY bit " + "(hw=0x%04x, count=%d, jiffies=%ld)\n", + hw_state, count, jiffies - (t - HZ)); + } + /* If timeout=0 then maximum timeout index is used. */ tmout = DIV_ROUND_UP(data->timeout_ns, host->ns_per_clk); tmout += data->timeout_clks; |