[RFT PATCH 7/8] clk: ti: clk-54xx: Prevent possible ERR_PTR dereference

From: Krzysztof Kozlowski
Date: Wed May 13 2015 - 02:55:28 EST


The return value of clk_get_sys() was immediately used in
clk_set_parent() and clk_set_rate(). The first one may return ERR_PTR
and the latter only checks if supplied argument is non-NULL.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
---
drivers/clk/ti/clk-54xx.c | 47 ++++++++++++++++++++++++++++++++---------------
1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/drivers/clk/ti/clk-54xx.c b/drivers/clk/ti/clk-54xx.c
index 96c69a335975..1e7ed6334ab4 100644
--- a/drivers/clk/ti/clk-54xx.c
+++ b/drivers/clk/ti/clk-54xx.c
@@ -222,39 +222,56 @@ static struct ti_dt_clk omap54xx_clks[] = {
{ .node_name = NULL },
};

-int __init omap5xxx_dt_clk_init(void)
+static void __init omap5xxx_dt_clk_abe_dpll_init(void)
{
int rc;
- struct clk *abe_dpll_ref, *abe_dpll, *sys_32k_ck, *usb_dpll;
-
- ti_dt_clocks_register(omap54xx_clks);
-
- omap2_clk_disable_autoidle_all();
+ struct clk *abe_dpll_ref, *abe_dpll, *sys_32k_ck;

abe_dpll_ref = clk_get_sys(NULL, "abe_dpll_clk_mux");
sys_32k_ck = clk_get_sys(NULL, "sys_32k_ck");
+ if (IS_ERR(abe_dpll_ref) || IS_ERR(sys_32k_ck)) {
+ pr_err("%s: failed to configure ABE DPLL!\n", __func__);
+ return;
+ }
+
rc = clk_set_parent(abe_dpll_ref, sys_32k_ck);
+
abe_dpll = clk_get_sys(NULL, "dpll_abe_ck");
- if (!rc)
+ if (!rc && !IS_ERR(abe_dpll))
rc = clk_set_rate(abe_dpll, OMAP5_DPLL_ABE_DEFFREQ);
if (rc)
pr_err("%s: failed to configure ABE DPLL!\n", __func__);

abe_dpll = clk_get_sys(NULL, "dpll_abe_m2x2_ck");
- if (!rc)
+ if (!rc && !IS_ERR(abe_dpll))
rc = clk_set_rate(abe_dpll, OMAP5_DPLL_ABE_DEFFREQ * 2);
if (rc)
pr_err("%s: failed to configure ABE m2x2 DPLL!\n", __func__);
+}

- usb_dpll = clk_get_sys(NULL, "dpll_usb_ck");
- rc = clk_set_rate(usb_dpll, OMAP5_DPLL_USB_DEFFREQ);
- if (rc)
- pr_err("%s: failed to configure USB DPLL!\n", __func__);
+static void __init omap5xxx_dt_clk_usb_dpll_init(const char *clk_name,
+ unsigned long rate)
+{
+ int rc = -EINVAL;
+ struct clk *clk;
+
+ clk = clk_get_sys(NULL, clk_name);
+ if (!IS_ERR(clk))
+ rc = clk_set_rate(clk, rate);

- usb_dpll = clk_get_sys(NULL, "dpll_usb_m2_ck");
- rc = clk_set_rate(usb_dpll, OMAP5_DPLL_USB_DEFFREQ/2);
if (rc)
- pr_err("%s: failed to set USB_DPLL M2 OUT\n", __func__);
+ pr_err("%s: failed to configure %s!\n", __func__, clk_name);
+}
+
+int __init omap5xxx_dt_clk_init(void)
+{
+ ti_dt_clocks_register(omap54xx_clks);
+
+ omap2_clk_disable_autoidle_all();
+
+ omap5xxx_dt_clk_abe_dpll_init();
+ omap5xxx_dt_clk_usb_dpll_init("dpll_usb_ck", OMAP5_DPLL_USB_DEFFREQ);
+ omap5xxx_dt_clk_usb_dpll_init("dpll_usb_m2_ck", OMAP5_DPLL_USB_DEFFREQ/2);

return 0;
}
--
1.9.1

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