Re: [PATCH V2 1/2] ASoC: fsl_asrc: replace the process_option table with function

Hi

On Thu, Apr 11, 2019 at 09:39:06AM +0000, S.j. Wang wrote:

quoted

+/*
+ * Select the pre-processing and post-processing options

By aligning with other function comments:
/**
 * Select the pre-processing and post-processing options

quoted

+ *
+ * Fsin: input sample rate
+ * Fsout: output sample rate

I would suggest to use inrate and outrate to keep naming consistent.

quoted

+ * pre_proc: return value for pre-processing option
+ * post_proc: return value for post-processing option  */ static int
+fsl_asrc_sel_proc(int Fsin, int Fsout, int *pre_proc, int *post_proc)
+{
+     bool det_out_op2_cond;
+     bool det_out_op0_cond;

By looking at the comments below. Probably better to rename them
        bool post_proc_cond2, post_proc_cond0;

quoted

+     /* Codition for selection of post-processing */

"Codition" -> "Conditions"

quoted

+     det_out_op2_cond = (((Fsin * 15 > Fsout * 16) & (Fsout < 56000)) |
+                                     ((Fsin > 56000) & (Fsout <
+ 56000)));

Combining Daniel's comments + indentation alignment:
        det_out_op2_cond = (Fsin * 15 > Fsout * 16 && Fsout < 56000) ||
                           (Fsin > 56000 && Fsout < 56000);

quoted

+     det_out_op0_cond = (Fsin * 23 < Fsout * 8);
+
+     /*
+      * unsupported case: Tsout>16.125*Tsin, and Tsout>8.125*Tsin.

Funny thing is that there'd be no point in checking the 16.125, if Tsout is
bigger than 8.125 times of Tsin, i.e. only one condition:
        Tsout > 8.125 * Tsin

quoted

+      * Tsout>16.125*Tsin -> Fsin * 8 > 129 * Fsout
+      * Tsout>8.125*Tsin  -> Fsin * 8 > 65 * Fsout
+      * Tsout>4.125*Tsin  -> Fsin * 8 > 33 * Fsout
+      * Tsout>1.875*Tsin  -> Fsin * 8 > 15 * Fsout

Took me a while to understand what it is saying....

Better to write like this:
        /* Does not support cases: Tsout > 8.125 * Tsin */
        if (Fsin * 8 > 65 * Fsout) {
                pair_err("Does not support %d > 8.125 * %d\n", Fsout, Fsin);
                return -EINVAL;
        }

        /* Otherwise, select pre_proc between [0, 2] */
        if (Fsin * 8 > 33 * Fsout)

quoted

+             *pre_proc = 2;
+     else if (Fsin * 8 > 15 * Fsout) {
+             if (Fsin > 152000)
+                     *pre_proc = 2;
+             else
+                     *pre_proc = 1;
+     } else if (Fsin < 76000)
+             *pre_proc = 0;
+     else if (Fsin > 152000)
+             *pre_proc = 2;
+     else
+             *pre_proc = 1;

<== Would look better by moving post_cond calculations here.

quoted

+     if (det_out_op2_cond)
+             *post_proc = 2;
+     else if (det_out_op0_cond)
+             *post_proc = 0;
+     else
+             *post_proc = 1;

And we could remove this check below:

quoted

+     /* unsupported options */
+     if (*pre_proc == 4 || *pre_proc == 5)
+             return -EINVAL;

So basically we are doing:
        1) Error out unsupported cases
        2) Select pre_proc
        3) Calculate conditions for post_proc
        4) Select post_proc

Thanks

Thanks for reviewing, will send v3.