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Date: Thu, 6 Jun 2024 14:15:04 -0700
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Subject: Re: [PATCH] hwmon: (cros-ec_hwmon) Fix access to restricted __le16
To: =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Cc: Tzung-Bi Shih <tzungbi@kernel.org>, chrome-platform@lists.linux.dev,
 linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org,
 Benson Leung <bleung@chromium.org>
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From: Guenter Roeck <linux@roeck-us.net>
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In-Reply-To: <a9409e1f-a6d1-4d97-86c5-acb11c0115af@t-8ch.de>
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On 6/6/24 13:48, Thomas Weißschuh wrote:
> On 2024-06-06 13:16:59+0000, Guenter Roeck wrote:
>> On 6/6/24 12:53, Thomas Weißschuh wrote:
>>> Thanks!
>>>
>>> On 2024-06-06 11:05:07+0000, Guenter Roeck wrote:
>>>> 0-day complains:
>>>>
>>>> drivers-hwmon-cros_ec_hwmon.c:sparse:sparse:cast-to-restricted-__le16
>>>>
>>>> Fix by using a __le16 typed variable as parameter to le16_to_cpu().
>>>>
>>>> Fixes: bc3e45258096 ("hwmon: add ChromeOS EC driver")
>>>> Cc: Thomas Weißschuh <linux@weissschuh.net>
>>>> Cc: Tzung-Bi Shih <tzungbi@kernel.org>
>>>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>>>
>>> Acked-by: Thomas Weißschuh <linux@weissschuh.net>
>>>
>>> Guenter, does sparse work locally for you?
>>>
>>
>> It does, but I use the version from git://repo.or.cz/smatch.git.
> 
> That does indeed look much better, thanks.
> 
> 
> I have another question about the endianness conversion in general.
> The only places I see doing a conversion are
> cros_ec_sensors_cmd_read_u16() and the original cros_ec hwmon driver.
> 
> Also the documentation of the EC protocol does not specify anything in
> that regard.
> Instead there is the following comment in host_event_set_bit():
> 
>     /*
>      * The overall host event implementation assumes it's running on and
>      * communicating with little-endian architectures.
>      */
> 
> Can the conversion be dropped?
> 


Unless it is wrong I don't see a reason to drop it.

Guenter