[PATCH v3] clk: zynqmp: fix compile testing without ZYNQMP_FIRMWARE

[Stephen Boyd]

Quoting Michal Simek (2021-06-22 03:15:11)
> When the firmware code is disabled, the incomplete error handling
> in the clk driver causes compile-time warnings:
> 
> drivers/clk/zynqmp/pll.c: In function 'zynqmp_pll_recalc_rate':
> drivers/clk/zynqmp/pll.c:147:29: error: 'fbdiv' is used uninitialized [-Werror=uninitialized]
>   147 |         rate =  parent_rate * fbdiv;
>       |                 ~~~~~~~~~~~~^~~~~~~
> In function 'zynqmp_pll_get_mode',
>     inlined from 'zynqmp_pll_recalc_rate' at drivers/clk/zynqmp/pll.c:148:6:
> drivers/clk/zynqmp/pll.c:61:27: error: 'ret_payload' is used uninitialized [-Werror=uninitialized]
>    61 |         return ret_payload[1];
>       |                ~~~~~~~~~~~^~~
> drivers/clk/zynqmp/pll.c: In function 'zynqmp_pll_recalc_rate':
> drivers/clk/zynqmp/pll.c:53:13: note: 'ret_payload' declared here
>    53 |         u32 ret_payload[PAYLOAD_ARG_CNT];
>       |             ^~~~~~~~~~~
> drivers/clk/zynqmp/clk-mux-zynqmp.c: In function 'zynqmp_clk_mux_get_parent':
> drivers/clk/zynqmp/clk-mux-zynqmp.c:57:16: error: 'val' is used uninitialized [-Werror=uninitialized]
>    57 |         return val;
>       |                ^~~
> 
> As it was apparently intentional to support this for compile testing
> purposes, change the code to have just enough error handling for the
> compiler to not notice the remaining bugs.
> 
> Fixes: 21f237534661 ("clk: zynqmp: Drop dependency on ARCH_ZYNQMP")
> Co-developed-by: Arnd Bergmann <arnd at arndb.de>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---

Applied to clk-next. I see this fixes a bug in this upcoming release but
I'm sure we can pick this back to stable tree in a week or so once the
merge window opens. It's not like this is fixing anything besides
compile testing anyway.