[Intel-gfx] [PATCH 3/7] i2c: designware-baytrail: Take punit lock on bus acquire

[Hans de Goede]

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 at redhat.com>
>> Tested-by: tagorereddy <tagore.chandan at 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