[linuxdc-dev]Patch for sound driver

[Adrian M. <ad...@mc...>]

This patch:

* removes some dead bits of code
* makes a few changes to speed up code execution at the margins
* improves responsiveness and decreases load on processor in low demand 
situations

I know mrbrown has in mind posting more patches when he returns from 
hibernation.


35c35
< #include "../sound_config.h"
---
> #include "sound_config.h"
179a180
> 	spu_write_wait();
222,225c223,224
< 	// Wait one second
< 	int j = jiffies + HZ;
< 	while (jiffies < j)
< 		schedule();
---
> 	// Wait a little
> 	schedule();
273,290d271
< static int aica_lock_channel(int channel)
< {
< 	//channels exist in blocks of 32 32-bit registers
< 	//beginning at 0xa0700000 for the SH4
< 	//...but there are only 64 of them!
< 	if ((channel > 63) || (channel < 0)) {
< 		DEBGM
< 		    ("Attempted to open a sound channel which does not exist\n");
< 		return -EINVAL;
< 	}
< 	return 0;
< }
< 
< static int aica_unlock_channel(int channel)
< {
< 
< 	return 0;
< }
329a311,313
> 	//Lock channels 1 & 2
> 	request_mem_region(0xa0700000, 0x100, "AICA Channels");
> 
331,336d314
< 	int err = aica_lock_channel(devc->channel);
< 	if (err != 0) {
< 		MOD_DEC_USE_COUNT;
< 		up(&dsp_mutex);
< 		return err;	//failed
< 	}
346,348d323
< 	} else if ((minor & 0xF) == SND_DEV_AUDIO) {
< 		chanh->sfmt = SM_8BIT;
< 		devc->sformat = AFMT_MU_LAW;
356c331
< 		aica_unlock_channel(devc->channel);
---
> 		release_mem_region(0xa0700000, 0x100);
437,438c412
< 	if (devc)
< 		aica_unlock_channel(devc->channel);
---
> 	release_mem_region(0xa0700000, 0x100);
457c431
< 	int z;
---
> 	int z, y, x, w;
461,462c435,437
< 			BUFFER3[z] = BUFFER[z * 2];
< 			BUFFER2[z] = BUFFER[z * 2 + 1];
---
> 		  x = z * 2;
> 			BUFFER3[z] = BUFFER[x];
> 			BUFFER2[z] = BUFFER[x + 1];
465,470c440,447
< 
< 		for (z = 0; z < *count_out / samplelength; z++) {
< 			BUFFER3[z * 2] = BUFFER[z * 4];
< 			BUFFER3[z * 2 + 1] = BUFFER[z * 4 + 1];
< 			BUFFER2[z * 2] = BUFFER[z * 4 + 2];
< 			BUFFER2[z * 2 + 1] = BUFFER[z * 4 + 3];
---
> 	  y = *count_out / samplelength;
> 		for (z = 0; z < y; z++) {
> 		  x = z * 2;
> 		  w = z * 4;
> 			BUFFER3[x] = BUFFER[w];
> 			BUFFER3[x + 1] = BUFFER[w + 1];
> 			BUFFER2[x] = BUFFER[w + 2];
> 			BUFFER2[x + 1] = BUFFER[w + 3];
489c466
< 		if (chanh->freq < 15000)
---
> 		if (chanh->freq < 23000)
491c468
< 						       5);
---
> 						       1);
506a484,488
> 			if (chanh->freq < 23000)
> 				interruptible_sleep_on_timeout(&
> 							       (devc->
> 								open_wait),
> 							       1);
536,540c518,519
< 	switch (devc->sformat) {
< 	case AFMT_U8:
< 		convert_u8tos8(BUFFER, count);
< 		break;
< 	}
---
> 	else if (devc->sformat == AFMT_U8) convert_u8tos8(BUFFER, count);
> 	
545c524,525
< 	}
---
> 		BUFFERR = BUFFER2;	
> } 
550,551d529
< 	if (stereo)
< 		BUFFERR = BUFFER2;
826c804
< 	    ("AICA audio device driver for Dreamcast Linux - ver 0.1-pre10\n");
---
> 	    ("AICA audio device driver for Dreamcast Linux - ver 0.1-pre12\n");