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From: Ben Walsh <ben@jubnut.com>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Benson Leung <bleung@chromium.org>, Tzung-Bi Shih <tzungbi@kernel.org>,
 Guenter Roeck <groeck@chromium.org>, chrome-platform@lists.linux.dev,
 linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] platform/chrome: cros_ec_lpc: Fix error code in
 cros_ec_lpc_mec_read_bytes()
In-Reply-To: <3226cba0-82c5-47a3-89da-01ffa935a9dc@moroto.mountain>
References: <e0b43fb5-ecc8-4fb4-9b76-c06dea8cc4c4@moroto.mountain>
 <87sexgrdk4.fsf@jubnut.com>
 <3226cba0-82c5-47a3-89da-01ffa935a9dc@moroto.mountain>
Date: Thu, 13 Jun 2024 19:20:32 +0100
Message-ID: <87sexgaemn.fsf@jubnut.com>
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Dan Carpenter <dan.carpenter@linaro.org> writes:

> On Thu, Jun 13, 2024 at 05:51:39PM +0100, Ben Walsh wrote:
>> 
>> Thanks for fixing this! Unfortunately `in_range` returns -EINVAL if
>> length == 0 (see the definition of `fwk_ec_lpc_mec_in_range`). I'm sure
>> this broke something in my testing, but I can't find what it was now.
>
> I don't think fwk_ec_lpc_mec_in_range() is upstream.  This email is the
> only reference I can find to it on the internet.

Sorry, I mean cros_ec_lpc_mec_in_range().

>  int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length)
>  {
>  	if (length == 0)
> -		return -EINVAL;
> +		return 0;
>  
>  	if (WARN_ON(mec_emi_base == 0 || mec_emi_end == 0))
>  		return -EINVAL;
>
> But I don't like how subtle that is.  Probably adding a check for
> for if (length == 0) to the  to cros_ec_lpc_mec_read_bytes() seems
> like the best option.  I guess option 2 is the best option.

Thanks. I'll check out Tzung-Bi's suggestions as well before we decide.