linux-kernel - soc: xilinx: vcu: issue with 2nd null check on pointer divider

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Message-ID: <60721f5a-15d2-46a1-aa0c-d6d599244cb2@gmail.com>
Date: Thu, 8 May 2025 11:21:05 +0100
From: "Colin King (gmail)" <colin.i.king@...il.com>
To: Michael Tretter <m.tretter@...gutronix.de>,
 "linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>
Cc: Stephen Boyd <sboyd@...nel.org>, Michal Simek <michal.simek@....com>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: soc: xilinx: vcu: issue with 2nd null check on pointer divider

Hi,

There seems to be an issue with the following function with the second 
check on if (!divider). Firstly this is redundant code since divider has
already been null checked, so I suspect it should be instead if (!mux) 
but I'm unsure if this is correct since the call to 
clk_hw_unregister_divider is not made.  Also if mux is null, isn't the 
call to clk_hw_unregister_mux() problematic as a null pointer is being 
passed to it.

static void xvcu_clk_hw_unregister_leaf(struct clk_hw *hw)
{
         struct clk_hw *gate = hw;
         struct clk_hw *divider;
         struct clk_hw *mux;

         if (!gate)
                 return;

         divider = clk_hw_get_parent(gate);
         clk_hw_unregister_gate(gate);
         if (!divider)
                 return;

         mux = clk_hw_get_parent(divider);
         clk_hw_unregister_mux(mux);
         if (!divider)
                 return;

         clk_hw_unregister_divider(divider);
}

Colin

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