Re: [PATCH v2 06/23] sunxi: Skip non-DM UART pin setup when PINCTRL=y

From: Andre Przywara <andre.przywara@arm.com>
To: Samuel Holland <samuel@sholland.org>
Cc: u-boot@lists.denx.de, Jagan Teki <jagan@amarulasolutions.com>,
	Sean Anderson <seanga2@gmail.com>, Simon Glass <sjg@chromium.org>,
	Heinrich Schuchardt <heinrich.schuchardt@canonical.com>,
	Heiko Schocher <hs@denx.de>,
	Joe Hershberger <joe.hershberger@ni.com>
Subject: Re: [PATCH v2 06/23] sunxi: Skip non-DM UART pin setup when PINCTRL=y
Date: Fri, 1 Apr 2022 00:19:26 +0100	[thread overview]
Message-ID: <20220401001926.32221fda@slackpad.lan> (raw)
In-Reply-To: <20220318035420.15058-7-samuel@sholland.org>

On Thu, 17 Mar 2022 22:54:03 -0500
Samuel Holland <samuel@sholland.org> wrote:

Hi Samuel,

> When a pinctrl driver is available, it will take care of setting up
> these pins. However, for now this code is still needed in SPL.
> 
> Reviewed-by: Simon Glass <sjg@chromium.org>
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
> 
> (no changes since v1)
> 
>  arch/arm/mach-sunxi/board.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm/mach-sunxi/board.c b/arch/arm/mach-sunxi/board.c
> index 0071de19ff..32e2477ae7 100644
> --- a/arch/arm/mach-sunxi/board.c
> +++ b/arch/arm/mach-sunxi/board.c
> @@ -79,6 +79,7 @@ ulong board_get_usable_ram_top(ulong total_size)
>  static int gpio_init(void)
>  {
>  	__maybe_unused uint val;
> +#if !CONFIG_IS_ENABLED(PINCTRL)

So first this looks somewhat redundant, since the whole function (and
its caller) is already wrapped in #ifdef CONFIG_SPL_BUILD. Unless you
plan to have DM_PINCTRL for the RISC-V SPL?

But more importantly this function is already a nested #ifdef
nightmare. I experimented with:
	if (CONFIG_IS_ENABLED(PINCTRL))
		return 0;
and the toolchain garbage collection did the rest. This naive
version breaks H6, AFAICS, but with a bit of refactoring this could be
solved. But this is probably something for an independent cleanup patch.

So: if you agree to the SPL == !PINCTRL redundancy, please drop this
patch. If you want to keep the extra check, please at least add a
comment after the #endif, and I will look at cleaning this up
separately.

Cheers,
Andre

>  #if CONFIG_CONS_INDEX == 1 && defined(CONFIG_UART0_PORT_F)
>  #if defined(CONFIG_MACH_SUN4I) || \
>      defined(CONFIG_MACH_SUN7I) || \
> @@ -166,6 +167,7 @@ static int gpio_init(void)
>  #else
>  #error Unsupported console port number. Please fix pin mux settings in board.c
>  #endif
> +#endif
>  
>  #ifdef CONFIG_SUN50I_GEN_H6
>  	/* Update PIO power bias configuration by copy hardware detected value */