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authorDmitry Osipenko <digetx@gmail.com>2021-05-16 19:30:37 +0300
committerThierry Reding <treding@nvidia.com>2021-05-31 15:16:26 +0200
commit78086386b3d1e363e2152066f48efcbdbb158d0f (patch)
treea722d5623f88bcfeed2154cca784c41f7dc24275
parent18a6a7150a894383e89152a820bd71d664628abd (diff)
clk: tegra: Don't allow zero clock rate for PLLs
Zero clock rate doesn't make sense for PLLs and tegra-clk driver enters into infinite loop on trying to calculate PLL parameters for zero rate. Make code to error out if requested rate is zero. Originally this trouble was found by Robert Yang while he was trying to bring up upstream kernel on Samsung Galaxy Tab, which happened due to a bug in Tegra DRM driver that erroneously sets PLL rate to zero. This issues came over again recently during of kernel bring up on ASUS TF700T. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
-rw-r--r--drivers/clk/tegra/clk-pll.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
index 823a567f2adc..eaa079c177c3 100644
--- a/drivers/clk/tegra/clk-pll.c
+++ b/drivers/clk/tegra/clk-pll.c
@@ -558,6 +558,9 @@ static int _calc_rate(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
u32 p_div = 0;
int ret;
+ if (!rate)
+ return -EINVAL;
+
switch (parent_rate) {
case 12000000:
case 26000000: