On Fri, Jan 22, 2010 at 4:03 PM, Mauro Carvalho Chehab
<mche...@infradead.org> wrote:
> I've checked the core and it does it on a balanced way. Yet, it is risky
> to assume that this will always happen, and having a bad, non-interrupt
> mutex there can lead to machine hangups.

The core does balance the calls (I actually submitted a patch last
year fixing a bug where it wasn't).  However, if the tuner driver
itself calls the i2c_gate_ctrl() function [and some tuners do do this]
then you would hit a deadlock if it were used with Manu's frontend
driver.

>> Today, there is no real problem if a particular call path attempts to
>> enable the gate if it is already open (or disable if it is already
>> closed).  With your proposed change, you will result in a deadlock.
>
> Precisely.

Of course, both of these concerns will be no longer be relevant now
that he is removing it from the dvb_frontend_ops (which means neither
the tuner nor the frontend will be able to manipulate the gate).

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com
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