Received-SPF: pass (google.com: domain of linux-kernel+bounces-69359-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Date: Sat, 17 Feb 2024 00:16:39 +0300
From: Evgeny Bachinin <eabachinin@salutedevices.com>
To: Viacheslav Bocharov <adeep@lexina.in>
CC: Neil Armstrong <neil.armstrong@linaro.org>, Jerome Brunet
	<jbrunet@baylibre.com>, Kevin Hilman <khilman@baylibre.com>, Martin
 Blumenstingl <martin.blumenstingl@googlemail.com>,
	<linux-amlogic@lists.infradead.org>, <linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>
Subject: Re: [PATCH 3/5] firmware: meson_sm: move common definitions to
 header file
Message-ID: <7zhsafmokydl3fxtfsjjnhizq6tidxsuefqcemsqqwqdje6m4p@gxfz3ajr76mv>
References: <20231122125643.1717160-1-adeep@lexina.in>
 <20231122125643.1717160-4-adeep@lexina.in>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20231122125643.1717160-4-adeep@lexina.in>
User-Agent: NeoMutt/20231006

On Wed, Nov 22, 2023 at 03:56:41PM +0300, Viacheslav Bocharov wrote:
> Move SM_CHIPID_* constants from firmware meson sm driver to
> header file.
> 
> Signed-off-by: Viacheslav Bocharov <adeep@lexina.in>
> ---
>  drivers/firmware/meson/meson_sm.c       | 4 ----
>  include/linux/firmware/meson/meson_sm.h | 4 ++++
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
> index 402851ed4ac0..96e50811336f 100644
> --- a/drivers/firmware/meson/meson_sm.c
> +++ b/drivers/firmware/meson/meson_sm.c
> @@ -240,10 +240,6 @@ struct meson_sm_firmware *meson_sm_get(struct device_node *sm_node)
>  }
>  EXPORT_SYMBOL_GPL(meson_sm_get);
>  
> -#define SM_CHIP_ID_LENGTH	119
> -#define SM_CHIP_ID_OFFSET	4
> -#define SM_CHIP_ID_SIZE		12
> -
>  static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
>  			 char *buf)
>  {
> diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h
> index 8eaf8922ab02..f62acd2bf52a 100644
> --- a/include/linux/firmware/meson/meson_sm.h
> +++ b/include/linux/firmware/meson/meson_sm.h
> @@ -7,6 +7,10 @@
>  #ifndef _MESON_SM_FW_H_
>  #define _MESON_SM_FW_H_
>  
> +#define SM_CHIP_ID_LENGTH	119

Does anybody know why this value is 119 bytes?
if in-shmem data, arrived from BL31, contains only up to 20 bytes
(in case of chipID v2):
+-----------+---------+---------------------------------+
| chipID ver|  cpu_id |        12b-serial               |
|  4 bytes  | 4 bytes |(per particular die unique data) |
+-----------+---------+---------------------------------+

> +#define SM_CHIP_ID_OFFSET	4
> +#define SM_CHIP_ID_SIZE		12

It seems that either the value (12) is incorrect or the current naming
is misleading. This is because the chipID is 16 bytes. Of course,
likely the SoC serial was meant here...

Furthermore, it appears that SM_CHIP_ID_SIZE is an unused symbol. It
has been unused since its creation in
0789724f86a5 ('firmware: meson_sm: Add serial number sysfs entry')

> +
>  enum {
>  	SM_EFUSE_READ,
>  	SM_EFUSE_WRITE,
> -- 
> 2.34.1
> 
> 

-- 
Best Regards,
Evgeny Bachinin