Re: [PATCH 15/27] ALSA: hda - Use timecounter_initialize interface

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 12/15/2017 10:40 PM, Takashi Iwai wrote:
On Fri, 15 Dec 2017 17:51:25 +0100,
Richard Cochran wrote:
On Fri, Dec 15, 2017 at 12:10:47PM +0100, Takashi Iwai wrote:

-	struct cyclecounter *cc = &azx_dev->tc.cc;
-	cc->read = azx_cc_read;
-	cc->mask = CLOCKSOURCE_MASK(32);
-	cc->mult = 125; /* saturation after 195 years */
-	cc->shift = 0;
I want to get away from this mess of open coded structure
initialization and use a proper functional interface instead.
I agree that a proper functional interface would be better, too.
But not a form like foo(501, 21, 10, 499, 5678).
In C syntax, you may more easily pass a wrong value than open codes.

  	nsec = 0; /* audio time is elapsed time since trigger */
-	timecounter_init(tc, nsec);
+	timecounter_initialize(tc,
+			       azx_cc_read,
+			       CLOCKSOURCE_MASK(32),
+			       125, /* saturation after 195 years */
+			       0,
+			       nsec);
Hmm, a function with so many arguments is difficult to remember and is
often error-prone.  By this transition, it becomes harder to read
through.
Please suggest a better way.
I have no good idea ATM, sorry.

Or can we provide simpler versions for covering some defaults?  At
least reducing the number of arguments would make things easier.
Thought about specifying 1. cyclecounter read func 2. frequency 3. width of counter as parameters here which can get rid of mult, shift params. But this is not easy as most of the drivers do not specify
cyclecounter frequency and instead hard-code the mult/shift factors.
How about passing initialized cyclecounter struct?

Takashi

_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel



[Index of Archives]     [ALSA User]     [Linux Audio Users]     [Kernel Archive]     [Asterisk PBX]     [Photo Sharing]     [Linux Sound]     [Video 4 Linux]     [Gimp]     [Yosemite News]

  Powered by Linux