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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>
This commit is contained in:
Sergei Shtylyov 2014-09-18 23:33:49 +04:00 committed by Ulf Hansson
parent b9bd7ff806
commit bb98d9d1d2
1 changed files with 9 additions and 0 deletions
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9
drivers/mmc/host/tmio_mmc_pio.c
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@ -1121,6 +1121,15 @@ int tmio_mmc_host_probe(struct tmio_mmc_host **host,
mmc->f_min = mmc->f_max / 512; 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 * While using internal tmio hardware logic for card detection, we need
* to ensure it stays powered for it to work. * to ensure it stays powered for it to work.