Re: [PATCH v2 04/12] tty: serial: samsung: prepare for different IO types

Greg KH
2024-01-04T15:32:59Z

On Thu, Dec 28, 2023 at 12:57:57PM +0000, Tudor Ambarus wrote:
> GS101's Connectivity Peripheral blocks (peric0/1 blocks) which
> include the I3C and USI (I2C, SPI, UART) only allow 32-bit
> register accesses. If using 8-bit register accesses, a SError
> Interrupt is raised causing the system unusable.
>
> Instead of specifying the reg-io-width = 4 everywhere, for each node,
> the requirement should be deduced from the compatible.
>
> Prepare the samsung tty driver to allow IO types different than
> UPIO_MEM. ``struct uart_port::iotype`` is an unsigned char where all
> its 8 bits are exposed to uapi. We can't make NULL checks on it to
> verify if it's set, thus always set it from the driver's data.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> ---
> v2: new patch
>
> drivers/tty/serial/samsung_tty.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index 66bd6c090ace..97ce4b2424af 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -72,6 +72,7 @@ struct s3c24xx_uart_info {
> const char *name;
> enum s3c24xx_port_type type;
> unsigned int port_type;
> + unsigned char iotype;
> unsigned int fifosize;
> unsigned long rx_fifomask;
> unsigned long rx_fifoshift;

Is there a reason you are trying to add unused memory spaces to this
structure for no valid reason? I don't think you could have picked a
more incorrect place in there to add this :)

Please fix.

thanks,

greg k-h