ti: clocks: Fix do_enable_clocks() to accept NULL pointers as input parameters

Up till this commit passing NULL as input parameter was allowed, but not
handled properly.

When one passed NULL to one of this function parameters, the code was
executed causing data abort.

However, what is more interesting, the abort was not caught because of code
execution in HYP mode with masked CPSR A bit ("Imprecise Data Abort mask bit).
The TI's AM57xx SoC switch to HYP mode with A bit masked in lowlevel_init.S
due to SMC call. Such operation (by default) is performed in SoC ROM code.

The problem would pop up when one:
- Switch back to SVC mode after disabling LPAE support
- Somebody enables A bit (by executing cpsie a asm instruction)

and then the previously described exception would be caught.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>

diff --git a/arch/arm/mach-omap2/clocks-common.c b/arch/arm/mach-omap2/clocks-common.c
index 84f93e73f6d09c99c3e9f42374a7c658747bab1c..93c4c6fe33e71fe0db9b6811b38a52ab54a6c44b 100644 (file)
--- a/arch/arm/mach-omap2/clocks-common.c
+++ b/arch/arm/mach-omap2/clocks-common.c
@@ -828,27 +828,29 @@ void do_enable_clocks(u32 const *clk_domains,
        u32 i, max = 100;
 
        /* Put the clock domains in SW_WKUP mode */
-       for (i = 0; (i < max) && clk_domains[i]; i++) {
+       for (i = 0; (i < max) && clk_domains && clk_domains[i]; i++) {
                enable_clock_domain(clk_domains[i],
                                    CD_CLKCTRL_CLKTRCTRL_SW_WKUP);
        }
 
        /* Clock modules that need to be put in HW_AUTO */
-       for (i = 0; (i < max) && clk_modules_hw_auto[i]; i++) {
+       for (i = 0; (i < max) && clk_modules_hw_auto &&
+                    clk_modules_hw_auto[i]; i++) {
                enable_clock_module(clk_modules_hw_auto[i],
                                    MODULE_CLKCTRL_MODULEMODE_HW_AUTO,
                                    wait_for_enable);
        };
 
        /* Clock modules that need to be put in SW_EXPLICIT_EN mode */
-       for (i = 0; (i < max) && clk_modules_explicit_en[i]; i++) {
+       for (i = 0; (i < max) && clk_modules_explicit_en &&
+                    clk_modules_explicit_en[i]; i++) {
                enable_clock_module(clk_modules_explicit_en[i],
                                    MODULE_CLKCTRL_MODULEMODE_SW_EXPLICIT_EN,
                                    wait_for_enable);
        };
 
        /* Put the clock domains in HW_AUTO mode now */
-       for (i = 0; (i < max) && clk_domains[i]; i++) {
+       for (i = 0; (i < max) && clk_domains && clk_domains[i]; i++) {
                enable_clock_domain(clk_domains[i],
                                    CD_CLKCTRL_CLKTRCTRL_HW_AUTO);
        }