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Subject: Re: [PATCH RFC 0/3] staging: r8188eu: avoid uninit value bugs
To:     "Fabio M. De Francesco" <fmdefrancesco@gmail.com>,
        Greg KH <gregkh@linuxfoundation.org>
Cc:     Larry.Finger@lwfinger.net, phil@philpotter.co.uk,
        straube.linux@gmail.com, linux-staging@lists.linux.dev,
        linux-kernel@vger.kernel.org, Martin Kaiser <martin@kaiser.cx>
References: <cover.1629479152.git.paskripkin@gmail.com>
 <435eea22-da31-1ebc-840c-ee9e42b27265@gmail.com> <YSJFhmTs74PUyo8b@kroah.com>
 <2244219.zNr1yEsLHP@localhost.localdomain>
From:   Pavel Skripkin <paskripkin@gmail.com>
Message-ID: <6182ed46-d79d-7f66-c7c0-096486410b4d@gmail.com>
Date:   Sun, 22 Aug 2021 16:31:31 +0300
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On 8/22/21 4:21 PM, Fabio M. De Francesco wrote:
> On Sunday, August 22, 2021 2:39:34 PM CEST Greg KH wrote:
>> On Sun, Aug 22, 2021 at 03:10:56PM +0300, Pavel Skripkin wrote:
>> > On 8/22/21 1:59 PM, Fabio M. De Francesco wrote:
>> > > On Sunday, August 22, 2021 12:09:29 PM CEST Pavel Skripkin wrote:
> [...]
>> > > So, it's up to the callers to test if (!_rtw_read*()) and then act
>> > > accordingly. If they get 0 they should know how to handle the errors.
>> > 
>> > Yes, but _rtw_read*() == 0 indicates 2 states:
>> > 	1. Error on transfer side
>> > 	2. Actual register value is 0
>> 
>> That's not a good design, it should be fixed.  Note there is the new
>> usb_control_msg_recv() function which should probably be used instead
>> here, to prevent this problem from happening.
> 
> I think that no functions should return 0 for signaling FAILURE. If I'm not
> wrong, the kernel quite always prefers to return 0 on SUCCESS and <0 on
> FAILURE. Why don't you just fix this?
> 

That's what I've done in v2. All rtw_read* family will have following 
prototype in v2:

int __must_check _rtw_read8(struct adapter *adapter, u32 addr, u8 *data);


Was it your idea, or you were talking about different approach?


With regards,
Pavel Skripkin