Re: [PATCH v4 5/6] drm/ssd130x: Implement ssd130x_write_cmd() on top of ssd130x_write_cmds()

[Andy Shevchenko]

On Tue, Aug 18, 2026 at 11:06:25AM +0300, Amit Barzilai wrote:
> ssd130x_write_cmd() and ssd130x_write_cmds() each carried their own
> regmap_write() loop over SSD13XX_COMMAND, differing only in how the caller
> supplies the bytes.
> 
> Turn ssd130x_write_cmd() into a thin variadic wrapper that collects its
> arguments into a small stack buffer and defers to ssd130x_write_cmds(), and
> move the protocol comment onto the latter, which is where the loop now
> lives.
> 
> No functional change: the bytes sent and the bus transactions used to send
> them are identical for every chip on both the I2C and SPI transports.

...

> +static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
> +			     /* u8 cmd, u8 param, ... */...)
> +{
> +	u8 buf[8];
> +	va_list ap;
> +
> +	if (drm_WARN_ON(&ssd130x->drm, count > ARRAY_SIZE(buf)))

For byte arrays sizeof() is sufficient.

> +		return -EINVAL;
> +
> +	va_start(ap, count);
> +	for (int i = 0; i < count; i++)
> +		buf[i] = va_arg(ap, int);
> +	va_end(ap);
> +
> +	return ssd130x_write_cmds(ssd130x, buf, count);
> +}

-- 
With Best Regards,
Andy Shevchenko