[alsa-devel] PATCH - ESI Juli driver
tiwai at suse.de
Mon Mar 17 16:17:59 CET 2008
At Mon, 17 Mar 2008 15:08:48 +0100,
Pavel Hofman wrote:
> Takashi Iwai wrote:
> > At Mon, 17 Mar 2008 10:37:22 +0100,
> > Pavel Hofman wrote:
> >> What would you recommend?
> > IMO, rate_code can be avoided. Instead of exposing the encoded value,
> > better to use the raw rate value as parameters.
> No problem. I just wanted to avoid the repeated conversion from the
> numerical rate to the card specific representation which is input
> information for all the rate-related code. ice1724 cards utilize
> MT_RATE, juli makes use of GPIO.
> If you are OK with the repeated conversion, I will remove this. I tried
> to keep the methods inline if possible.
Usually you don't have to specify inline expclitily unless it's really
the time-critical code path. And the code path of the rate setting is
certainly no such a thing.
> > And, the texts inf rates_info can be generated dynamically.
> For obvious reasons I tried changing ice1724 as little as possible. That
> is why I kept the original code, only rearranged it.
> I can change the way texts in rates_info are generated. Still there will
> have to be some callback as juli has a different list of rates.
> > So, what we need primarily are callbacks to get and set the current
> > rate setting. Suppose rate=0 as SPDIF-in, we can pass the raw rate
> > value. Then snd_vt1724_pro_internal_clock_get() would just a function
> > to get the current rate and compares it with the given rate_info
> > value, returns the index.
> I am afraid I do not understand what to change in
> snd_vt1724_pro_internal_clock_get(). It seems fairly logical, I made
> only minor changes - is_spdif_master used in other parts of the code,
> get_rate_index with a simple meaning.
Yeah, your change is logical -- simply convert some code snippets to
callbacks. But, this isn't really good for maintenance for a long
term. I prefer a bit more straight way if we really change
something. And, indeed we do need to change the stuff for rate
> > How to set stream-specific hw_params is another question. But surely
> > we can cut off a bit more.
> We probably can, by rewriting portions of the original well-tested
> ice1724 code. I really wanted to avoid that and changed by callbacks
> only the card-specific portions.
> OK, I will remove the rate_code conversions, the new overhead will be
> low and one abstraction will be removed.
> For the rest, please state you objectives. Either cutting a few of the
> callbacks by non-trivial rewrite of the original ice1724 code, or
> keeping the remaining callbacks and the well-tested code.
Don't be too nervous about changing the ice1724 code right now :)
We would need the rewrite of core codes anyway because of other
problems in Maya44. And, I believe we can fix more than we might
break by such a restructuring in the end. The current ice1724.c is
way too complex due to its history, derived from ice1712.c.
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