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[1/5] soc/tegra: pmc: Guard against uninitialised PMC clock

Message ID 1477164236-29351-2-git-send-email-jonathanh@nvidia.com
State Accepted
Delegated to: Thierry Reding
Headers show

Commit Message

Jon Hunter Oct. 22, 2016, 7:23 p.m. UTC
It is possible for the public functions, tegra_io_rail_power_on/off()
to be called before the PMC device has been probed. If this happens
then the pmc->clk member will not be initialised and the call to
clk_get_rate() in tegra_io_rail_prepare() will return zero and lead
to a divide-by-zero exception. The function clk_get_rate() will return
zero if a NULl clk pointer is passed. Therefore, rather that checking
if pmc->clk is initialised, fix this by checking the return value for
clk_get_rate() to make sure it is not zero.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
 drivers/soc/tegra/pmc.c | 2 ++
 1 file changed, 2 insertions(+)
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diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 7792ed88d80b..c99580aabcf6 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -931,6 +931,8 @@  static int tegra_io_rail_prepare(unsigned int id, unsigned long *request,
 	rate = clk_get_rate(pmc->clk);
+	if (!rate)
+		return -ENODEV;
 	tegra_pmc_writel(DPD_SAMPLE_ENABLE, DPD_SAMPLE);