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authorNishanth Menon <nm@ti.com>2014-08-18 18:56:54 +0200
committerTero Kristo <t-kristo@ti.com>2014-08-21 17:04:16 +0200
commit2f1032517623b70920d99529e5c87c8c680ab8bf (patch)
treee69dbbf4e0bf9b0ceb07591eea328945936e1531 /drivers/clk
parentLinux 3.17-rc1 (diff)
downloadlinux-2f1032517623b70920d99529e5c87c8c680ab8bf.tar.xz
linux-2f1032517623b70920d99529e5c87c8c680ab8bf.zip
clk: ti: divider: Provide error check for incoming parameters in set_rate
Check for valid parameters in check rate. Else, we end up getting errors like: [ 0.000000] Division by zero in kernel. [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.0-rc1 #1 [ 0.000000] [<c0015160>] (unwind_backtrace) from [<c0011978>] (show_stack+0x10/0x14) [ 0.000000] [<c0011978>] (show_stack) from [<c055f5f4>] (dump_stack+0x78/0x94) [ 0.000000] [<c055f5f4>] (dump_stack) from [<c02e17cc>] (Ldiv0+0x8/0x10) [ 0.000000] [<c02e17cc>] (Ldiv0) from [<c047d228>] (ti_clk_divider_set_rate+0x14/0x14c) [ 0.000000] [<c047d228>] (ti_clk_divider_set_rate) from [<c047a938>] (clk_change_rate+0x138/0x180) [ 0.000000] [<c047a938>] (clk_change_rate) from [<c047a908>] (clk_change_rate+0x108/0x180) This occurs as part of the inital clock tree update of child clock nodes where new_rate could be 0 for non functional clocks. Fixes: b4761198bfaf296 ("CLK: ti: add support for ti divider-clock") Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Tero Kristo <t-kristo@ti.com>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/ti/divider.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c
index e6aa10db7bba..a837f703be65 100644
--- a/drivers/clk/ti/divider.c
+++ b/drivers/clk/ti/divider.c
@@ -211,11 +211,16 @@ static long ti_clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
static int ti_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
- struct clk_divider *divider = to_clk_divider(hw);
+ struct clk_divider *divider;
unsigned int div, value;
unsigned long flags = 0;
u32 val;
+ if (!hw || !rate)
+ return -EINVAL;
+
+ divider = to_clk_divider(hw);
+
div = DIV_ROUND_UP(parent_rate, rate);
value = _get_val(divider, div);