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Subject: Re: [PATCH] drivers: watchdog: rdc321x_wdt: Fix race condition bugs
To:     Guenter Roeck <linux@roeck-us.net>, madhuparnabhowmik10@gmail.com
Cc:     wim@linux-watchdog.org, linux-watchdog@vger.kernel.org,
        linux-kernel@vger.kernel.org, andrianov@ispras.ru,
        ldv-project@linuxtesting.org
References: <20200807112902.28764-1-madhuparnabhowmik10@gmail.com>
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 <8dca64a1-8cd9-6a41-b61d-1c4c14e5cd5e@gmail.com>
 <bc8c5d7d-91a4-e955-854f-eef88812ac1a@roeck-us.net>
From:   Florian Fainelli <f.fainelli@gmail.com>
Message-ID: <1b9db5ad-0edf-091b-a04e-a8f3a6ac08e2@gmail.com>
Date:   Fri, 7 Aug 2020 13:09:02 -0700
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On 8/7/2020 12:08 PM, Guenter Roeck wrote:
> On 8/7/20 11:08 AM, Florian Fainelli wrote:
>>
>>
>> On 8/7/2020 9:21 AM, Guenter Roeck wrote:
>>> On Fri, Aug 07, 2020 at 04:59:02PM +0530, madhuparnabhowmik10@gmail.com wrote:
>>>> From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>>>>
>>>> In rdc321x_wdt_probe(), rdc321x_wdt_device.queue is initialized
>>>> after misc_register(), hence if ioctl is called before its
>>>> initialization which can call rdc321x_wdt_start() function,
>>>> it will see an uninitialized value of rdc321x_wdt_device.queue,
>>>> hence initialize it before misc_register().
>>>> Also, rdc321x_wdt_device.default_ticks is accessed in reset()
>>>> function called from write callback, thus initialize it before
>>>> misc_register().
>>>>
>>>> Found by Linux Driver Verification project (linuxtesting.org).
>>>>
>>>> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>>>
>>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>>>
>>> Having said that ... this is yet another potentially obsolete driver.
>>> You are really wasting your (and, fwiw, my) time.
>>>
>>> Florian, any thoughts if support for this chip can/should be deprecated
>>> or even removed ?
>>
>> I am still using my rdc321x-based SoC, so no, this is not obsolete as
>> far as I am concerned, time permitting, modernizing the driver is on my
>> TODO after checking/fixing the Ethernet driver first.
>>
> 
> Do you have a manual ? I'd give it a try if you can test it - conversion
> should be simple enough (I have a coccinelle script which partially
> automates it), but this chip seems to have a fast timeout, and the
> comments in the code ("set the timeout to 81.92 us") seem to be quite
> obviously wrong.

Yes, there is a public manual for that SoC, search for RDC R8610 and the
first link you find should be a 276 page long manual for the SoC.

I probably won't be able to test anything until the middle of next week
though.
--
Florian