From 2f1032517623b70920d99529e5c87c8c680ab8bf Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Mon, 18 Aug 2014 11:56:54 -0500 Subject: [PATCH] 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] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [ 0.000000] [] (show_stack) from [] (dump_stack+0x78/0x94) [ 0.000000] [] (dump_stack) from [] (Ldiv0+0x8/0x10) [ 0.000000] [] (Ldiv0) from [] (ti_clk_divider_set_rate+0x14/0x14c) [ 0.000000] [] (ti_clk_divider_set_rate) from [] (clk_change_rate+0x138/0x180) [ 0.000000] [] (clk_change_rate) from [] (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 Signed-off-by: Tero Kristo --- drivers/clk/ti/divider.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) 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); -- 2.11.0