Re: [PATCH v6 2/5] i3c: master: svc: Replace bool rnw with union for HDR support

From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Frank Li <Frank.Li@nxp.com>
Cc: "Alexandre Belloni" <alexandre.belloni@bootlin.com>,
	"Miquel Raynal" <miquel.raynal@bootlin.com>,
	"Jonathan Cameron" <jic23@kernel.org>,
	"David Lechner" <dlechner@baylibre.com>,
	"Nuno Sá" <nuno.sa@analog.com>,
	"Andy Shevchenko" <andy@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org,
	imx@lists.linux.dev, linux-iio@vger.kernel.org,
	joshua.yeong@starfivetech.com, devicetree@vger.kernel.org
Subject: Re: [PATCH v6 2/5] i3c: master: svc: Replace bool rnw with union for HDR support
Date: Thu, 23 Oct 2025 11:26:37 +0300	[thread overview]
Message-ID: <aPnmvepToKtZnAI-@smile.fi.intel.com> (raw)
In-Reply-To: <20251014-i3c_ddr-v6-2-3afe49773107@nxp.com>

On Tue, Oct 14, 2025 at 12:40:01PM -0400, Frank Li wrote:
> Replace the bool rnw field with a union in preparation for adding HDR
> support. HDR uses a cmd field instead of the rnw bit to indicate read or
> write direction.
> 
> Add helper function svc_cmd_is_read() to check transfer direction.
> 
> Add a local variable 'rnw' in svc_i3c_master_priv_xfers() to avoid
> repeatedly accessing xfers[i].rnw.
> 
> No functional change.

...

>  struct svc_i3c_cmd {
>  	u8 addr;
> -	bool rnw;
> +	union {
> +		bool rnw;
> +		u8 cmd;
> +		u32 rnw_cmd;
> +	};

Same Q, what is the selector?

>  	u8 *in;
>  	const void *out;
>  	unsigned int len;

>  }

> +static bool svc_cmd_is_read(u32 rnw_cmd, u32 type)
> +{
> +	return rnw_cmd;
> +}

Useless?

-- 
With Best Regards,
Andy Shevchenko