Re: [PATCH v2] clk: renesas: r9a06g032: Drop __packed for portability

[Stephen Rothwell]

Hi Geert,

On Mon, 30 Nov 2020 09:57:43 +0100 Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:
>
> The R9A06G032 clock driver uses an array of packed structures to reduce
> kernel size.  However, this array contains pointers, which are no longer
> aligned naturally, and cannot be relocated on PPC64.  Hence when
> compile-testing this driver on PPC64 with CONFIG_RELOCATABLE=y (e.g.
> PowerPC allyesconfig), the following warnings are produced:
> 
>     WARNING: 136 bad relocations
>     c000000000616be3 R_PPC64_UADDR64   .rodata+0x00000000000cf338
>     c000000000616bfe R_PPC64_UADDR64   .rodata+0x00000000000cf370
>     ...
> 
> Fix this by dropping the __packed attribute from the r9a06g032_clkdesc
> definition, trading a small size increase for portability.
> 
> This increases the 156-entry clock table by 1 byte per entry, but due to
> the compiler generating more efficient code for unpacked accesses, the
> net size increase is only 76 bytes (gcc 9.3.0 on arm32).
> 
> Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Fixes: 4c3d88526eba2143 ("clk: renesas: Renesas R9A06G032 clock driver")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> v2:
>   - Fix authorship.
> ---
>  drivers/clk/renesas/r9a06g032-clocks.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/renesas/r9a06g032-clocks.c b/drivers/clk/renesas/r9a06g032-clocks.c
> index d900f6bf53d0b944..892e91b92f2c80f5 100644
> --- a/drivers/clk/renesas/r9a06g032-clocks.c
> +++ b/drivers/clk/renesas/r9a06g032-clocks.c
> @@ -55,7 +55,7 @@ struct r9a06g032_clkdesc {
>  			u16 sel, g1, r1, g2, r2;
>  		} dual;
>  	};
> -} __packed;
> +};
>  
>  #define I_GATE(_clk, _rst, _rdy, _midle, _scon, _mirack, _mistat) \
>  	{ .gate = _clk, .reset = _rst, \
> -- 
> 2.25.1
> 

Tested-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> # PowerPC allyesconfig build

-- 
Cheers,
Stephen Rothwell

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