From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hans de Goede <hdegoede@redhat.com>
Subject: Re: [PATCH 3/7] i2c: designware-baytrail: Take punit lock on bus
 acquire
Date: Sun, 8 Jan 2017 16:39:31 +0100
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To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Daniel Vetter <daniel.vetter@intel.com>, Jani Nikula <jani.nikula@linux.intel.com>, =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= <ville.syrjala@linux.intel.com>, Jarkko Nikula <jarkko.nikula@linux.intel.com>, Wolfram Sang <wsa@the-dreams.de>, Len Brown <lenb@kernel.org>
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>, dri-devel@lists.freedesktop.org, Mika Westerberg <mika.westerberg@linux.intel.com>, Takashi Iwai <tiwai@suse.de>, "russianneuromancer @ ya . ru" <russianneuromancer@ya.ru>, linux-i2c@vger.kernel.org

Hi,

On 08-01-17 16:27, Andy Shevchenko wrote:
> On Sun, 2017-01-08 at 14:44 +0100, Hans de Goede wrote:
>> Take the punit lock to stop others from accessing the punit while the
>> pmic i2c bus is in use. This is necessary because accessing the punit
>> from the kernel may result in the punit trying to access the pmic i2c
>> bus, which results in a hang when it happens while we own the pmic i2c
>> bus semaphore.
>>
>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> Tested-by: tagorereddy <tagore.chandan@gmail.com>
>> ---
>>  drivers/i2c/busses/i2c-designware-baytrail.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c
>> b/drivers/i2c/busses/i2c-designware-baytrail.c
>> index 3effc9a..cf7a2a0 100644
>> --- a/drivers/i2c/busses/i2c-designware-baytrail.c
>> +++ b/drivers/i2c/busses/i2c-designware-baytrail.c
>>
>
>> @@ -62,6 +62,8 @@ static void reset_semaphore(struct dw_i2c_dev *dev)
>
>> +	iosf_mbi_punit_unlock();
>
>> @@ -79,6 +81,8 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev
>> +	iosf_mbi_punit_lock();
>
> For me it looks a bit asymmetrical.
>
> Can we use acquire()/release()?

Sure I can change things to use acquire()/release() instead. I will
change this for v2.

Regards,

Hans