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From: Joy Chakraborty <joychakr@google.com>
Date: Wed, 12 Jun 2024 23:39:14 +0530
Message-ID: <CAOSNQF25nducTP-s5T55r6kJT9R13mEy5TQwrxr6JtEoiq=W6w@mail.gmail.com>
Subject: Re: [PATCH] rtc: cmos: Fix return value of nvmem callbacks
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>, 
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>, linux-rtc@vger.kernel.org, 
	linux-kernel@vger.kernel.org, stable@vger.kernel.org
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On Wed, Jun 12, 2024 at 2:53=E2=80=AFPM Dan Carpenter <dan.carpenter@linaro=
.org> wrote:
>
> On Wed, Jun 12, 2024 at 08:36:35AM +0000, Joy Chakraborty wrote:
> > Read/write callbacks registered with nvmem core expect 0 to be returned
> > on success and a negative value to be returned on failure.
> >
> > cmos_nvram_read()/cmos_nvram_write() currently return the number of
> > bytes read or written, fix to return 0 on success and -EIO incase numbe=
r
> > of bytes requested was not read or written.
> >
> > Fixes: 8b5b7958fd1c ("rtc: cmos: use generic nvmem")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Joy Chakraborty <joychakr@google.com>
> > ---
>
> Thanks!
>
> Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
>
> After we fix all the these, can we add a warning once message to detect
> when people introduce new bugs?  It could either go into
> __nvmem_reg_read/write() or bin_attr_nvmem_read/write().  I think
> bin_attr_nvmem_read() is the only caller where the buggy functions work
> but that's the caller that most people use I guess.
>

Sure I can do that.
Yes, I think most users use this via sysfs using bin_attr_nvmem_read()
hence it works.

Thanks
Joy

> regards,
> dan carpenter
>