mmc: tmio: prevent endless loop in tmio_mmc_set_clock()
I spent a couple of days with the driver just hanging due to me forgetting to
specify the external crystal frequency, so that clk_get_rate() returned 0 and
thus the loop in tmio_mmc_set_clock() never ended. I don't think that's an
acceptable behavior, so I suggest that the minimum frequency is checked for 0
in tmio_mmc_host_probe().
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Ian Molton <ian.molton@codethink.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index 692e578..e487ba4 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -1122,6 +1122,15 @@
}
/*
+ * Check the sanity of mmc->f_min to prevent tmio_mmc_set_clock() from
+ * looping forever...
+ */
+ if (mmc->f_min == 0) {
+ ret = -EINVAL;
+ goto host_free;
+ }
+
+ /*
* While using internal tmio hardware logic for card detection, we need
* to ensure it stays powered for it to work.
*/