Re: [PATCH] pinctrl: aspeed: Force to disable the function's signal

From: Linus Walleij
Date: Wed Aug 31 2022 - 08:15:24 EST


On Thu, Aug 18, 2022 at 12:18 PM Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> wrote:

> When the driver want to disable the signal of the function, it doesn't
> need to query the state of the mux function's signal on a pin. The
> condition below will miss the disable of the signal:
> Ball | Default | P0 Signal | P0 Expression | Other
> -----+---------+-----------+-----------------------------+----------
> E21 GPIOG0 SD2CLK SCU4B4[16]=1 & SCU450[1]=1 GPIOG0
> -----+---------+-----------+-----------------------------+----------
> B22 GPIOG1 SD2CMD SCU4B4[17]=1 & SCU450[1]=1 GPIOG1
> -----+---------+-----------+-----------------------------+----------
> Assume the register status like below:
> SCU4B4[16] == 1 & SCU4B4[17] == 1 & SCU450[1]==1
> After the driver set the Ball E21 to the GPIOG0:
> SCU4B4[16] == 0 & SCU4B4[17] == 1 & SCU450[1]==0
> When the driver want to set the Ball B22 to the GPIOG1, the condition of
> the SD2CMD will be false causing SCU4B4[17] not to be cleared.
>
> Signed-off-by: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>

Patch applied!

Yours,
Linus Walleij