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path: root/drivers/mmc/host/mvsdio.c
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Diffstat (limited to 'drivers/mmc/host/mvsdio.c')
-rw-r--r--drivers/mmc/host/mvsdio.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/mmc/host/mvsdio.c b/drivers/mmc/host/mvsdio.c
index 9d3cfa9909c..b56d72ff06e 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;