From bb98d9d1d2e791f368295c9c09c9a03fe3ac0e62 Mon Sep 17 00:00:00 2001 From: Sergei Shtylyov Date: Thu, 18 Sep 2014 23:33:49 +0400 Subject: [PATCH] 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 Acked-by: Ian Molton Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson --- drivers/mmc/host/tmio_mmc_pio.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c index 692e578cf4d7..e487ba4bb01a 100644 --- a/drivers/mmc/host/tmio_mmc_pio.c +++ b/drivers/mmc/host/tmio_mmc_pio.c @@ -1121,6 +1121,15 @@ int tmio_mmc_host_probe(struct tmio_mmc_host **host, mmc->f_min = mmc->f_max / 512; } + /* + * 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.