On 27.01.2014 19:45, Michael Krufky wrote:
On Sun, Jan 26, 2014 at 7:39 PM, Antti Palosaari <crope@xxxxxx> wrote:
On 27.01.2014 02:28, Devin Heitmueller wrote:
On Sun, Jan 26, 2014 at 7:16 PM, Antti Palosaari <crope@xxxxxx> wrote:
Driver conversion from proprietary DVB tuner model to more
general I2C driver model.
Mike should definitely weigh in on this. Eliminating the existing
model of using dvb_attach() for tuners is something that needs to be
considered carefully, and this course of action should be agreed on by
the subsystem maintainers before we start converting drivers. This
could be particularly relevant for hybrid tuners where the driver
instance is instantiated via tuner-core using dvb_attach() for the
analog side.
In the meantime, this change makes this driver work differently than
every other tuner in the tree.
Heh, it is quite stupid to do things otherwise than rest of the kernel and
also I think it is against i2c documentation. For more we refuse to use
kernel standard practices the more there will be problems in a long ran.
There is things that are build top of these standard models and if you are
using some proprietary method, then you are without these services. I think
it was regmap which I was looking once, but dropped it as it requires i2c
client.
Also, I already implemented one tuner driver using standard I2C model. If
there will be problems then those are surely fixable.
regards
Antti
Devin is right- I should have been cc'd on this. Please remember to
cc me on any DVB or tuner (both analog and digital) subsystem-level
changes.
What Devin probably doesn't realize, however, is that I have basically
already agreed on this change -- this, overall, will be a very
positive move for the media subsystem. We just need to do it
correctly, subsystem-wide.
But just because this is a good idea, its no reason to call the
current mechanism 'quite stupid' .. We're all working together here,
let's not belittle the work that others have done in the past. I'd
rather just look forward and build a better codebase for the future
:-)
Antti submitted similar patches a few months ago - I have to review
his newer series and see if anything has changed. My goal would be to
commit these patches into a new branch and work on converting the
entire tuner tree to the newer method, only merging to master once all
is done and tested.
My biggest point was to criticize that general resistance of new design
models which has been DVB side, not only that simple change but many
others too. I am pretty sure the many "mistakes" are taken when there
has not been better alternative available at the time, and later was
developed proper solution, which is not still taken into use.
I have also feeling that these wrong solutions and design models used
are one source of problems we have. All the chip I/Os should be modeled
in a standard manner to make sure it is possible to interconnect
flexible. GPIOs should be implemented as kernel GPIOs. I2C should be
implemented as kernel I2C. Clock should be implemented as a kernel
clock. Chip power-management should be implement as regulator (or what
ever that is). TS interface also should be modeled and implement in a
standard manner. Implementing things like that makes it possible to
interconnect complex hardware without fearing some small change will
break functionality because of some home-brew solution.
regards
Antti
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http://palosaari.fi/
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