Re: cx18: "missing audio" for analog recordings

[Mark Lord <mlord@pobox.com>]

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On 15/03/10 07:51 AM, Andy Walls wrote:
> On Sun, 2010-03-14 at 22:48 -0400, Mark Lord wrote:
>> On 03/02/10 07:40, Andy Walls wrote:
..
>> after updating to the tip of the v4l2-dvb git tree last week,
>> I've been hitting the "no audio" on analog recordings bug much more often.
>>
>> Digging through google, it appears this problem has been around as long
>> as the cx18 driver has existed, with no clear resolution.  Lots of people
>> have reported it to you before, and nobody has found a silver bullet fix.
..
> Here are all the potential problem areas I can think of:
>
> 1. A/V digitizer/decoder audio detection firmware load and init.  (I've
> added firmware readback verification to try and head this off.)
>
> 2. A/V digitizer decoder audio microcontroller hard reset and "soft"
> reset sequencing.  (I think the cx18 driver has this wrong ATM.)
>
> 3. APU load and init.  (The double load is to fix a DTV TS stream bug on
> every other APU&  CPU firmware load sequence.  The APU_AI_RESET is to
> fix the audio bitrate problem on first capture after a double firmware
> load.)
>
> 4. AI1 Mux setting failing when switching between the internal A/V
> decoder's I2S output and the external I2S inputs.  (I thought I had this
> fixed, but I don't have detailed register specs for that register - so
> maybe not.)
>
> 5. A/V decoder audio clock PLL stops operating due to being programmed
> out of range.  (This was a problem for 32 ksps audio a while ago, but
> I'm pretty confident I have it fixed.)
>
> 6. A/V decoder analog frontend setup for SIF wrong?.  (I fixed this due
> to a problen Helen Buus reported with cable TV.)
>
> I think #2 is the real problem.  I just started to disassmble the
> digitizer firmware 2 nights ago to see if I could get some insight as to
> how to properly reset it.
>
> I've got a first WAG at fixing the resets of the audio microcontroller's
> resets at:
>
> 	http://linuxtv.org/hg/~awalls/cx18-audio
>
> If it doesn't work, change the CXADEC_AUDIO_SOFT_RESET register define
> from 0x810 to 0x9cc, although that may not work either.
..
> Thanks for the troubleshooting and reporting.
..

Back at this again today, after a month away from it -- getting tired
of watching "Survivor" with closed-captioning instead of audio.  :)

I pulled your (Andy) repository today, and merged the cx18 audio reset
changes from it into today's tip from v4l-dvb.  Patch attached for reference.

So far, so good.  I'll keep tabs on it over time, and see if the audio
is stable, or if it still fails once in a while.

Cheers
-- 
Mark Lord
Real-Time Remedies Inc.
mlord@pobox.com

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--- v4l-dvb-7c0b887911cf/linux/drivers/media/video/cx18/cx18-av-audio.c	2010-04-05 22:56:43.000000000 -0400
+++ patched/linux/drivers/media/video/cx18/cx18-av-audio.c	2010-03-13 22:06:55.000000000 -0500
@@ -305,14 +305,14 @@
 	struct cx18_av_state *state = &cx->av_state;
 	u8 v;
 
+	/* assert soft reset */
+	v = cx18_av_read(cx, CXADEC_AUDIO_SOFT_RESET) | 0x01;
+	cx18_av_write_expect(cx, CXADEC_AUDIO_SOFT_RESET, v, v, 0x0f);
+
 	/* stop microcontroller */
 	v = cx18_av_read(cx, 0x803) & ~0x10;
 	cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
 
-	/* assert soft reset */
-	v = cx18_av_read(cx, 0x810) | 0x01;
-	cx18_av_write_expect(cx, 0x810, v, v, 0x0f);
-
 	/* Mute everything to prevent the PFFT! */
 	cx18_av_write(cx, 0x8d3, 0x1f);
 
@@ -330,16 +330,17 @@
 
 	set_audclk_freq(cx, state->audclk_freq);
 
-	/* deassert soft reset */
-	v = cx18_av_read(cx, 0x810) & ~0x01;
-	cx18_av_write_expect(cx, 0x810, v, v, 0x0f);
-
 	if (state->aud_input > CX18_AV_AUDIO_SERIAL2) {
+		/* start microcontroller */
 		/* When the microcontroller detects the
 		 * audio format, it will unmute the lines */
 		v = cx18_av_read(cx, 0x803) | 0x10;
 		cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
 	}
+
+	/* deassert soft reset */
+	v = cx18_av_read(cx, CXADEC_AUDIO_SOFT_RESET) & ~0x01;
+	cx18_av_write_expect(cx, CXADEC_AUDIO_SOFT_RESET, v, v, 0x0f);
 }
 
 static int get_volume(struct cx18 *cx)
@@ -449,12 +450,13 @@
 		 * changes to the mute register. */
 		v = cx18_av_read(cx, 0x803);
 		if (mute) {
-			/* disable microcontroller */
+			/* stop microcontroller */
 			v &= ~0x10;
 			cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
+			/* mute all of Path 1 */
 			cx18_av_write(cx, 0x8d3, 0x1f);
 		} else {
-			/* enable microcontroller */
+			/* start microcontroller */
 			v |= 0x10;
 			cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
 		}
@@ -471,22 +473,29 @@
 	int retval;
 	u8 v;
 
+	/* assert soft reset */
+	v = cx18_av_read(cx, CXADEC_AUDIO_SOFT_RESET) | 0x1;
+	cx18_av_write_expect(cx, CXADEC_AUDIO_SOFT_RESET, v, v, 0x0f);
+
 	if (state->aud_input > CX18_AV_AUDIO_SERIAL2) {
+		/* stop microcontroller */
 		v = cx18_av_read(cx, 0x803) & ~0x10;
 		cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
+		/* mute all of Path 1 */
 		cx18_av_write(cx, 0x8d3, 0x1f);
 	}
-	v = cx18_av_read(cx, 0x810) | 0x1;
-	cx18_av_write_expect(cx, 0x810, v, v, 0x0f);
 
 	retval = set_audclk_freq(cx, freq);
 
-	v = cx18_av_read(cx, 0x810) & ~0x1;
-	cx18_av_write_expect(cx, 0x810, v, v, 0x0f);
 	if (state->aud_input > CX18_AV_AUDIO_SERIAL2) {
+		/* start microcontroller */
 		v = cx18_av_read(cx, 0x803) | 0x10;
 		cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
 	}
+
+	/* deassert soft reset */
+	v = cx18_av_read(cx, CXADEC_AUDIO_SOFT_RESET) & ~0x1;
+	cx18_av_write_expect(cx, CXADEC_AUDIO_SOFT_RESET, v, v, 0x0f);
 	return retval;
 }
 
diff -u --recursive --new-file --exclude='.*' --exclude='*.[osa]' --exclude=System.map --exclude='*.orig' --exclude='*.lds' --exclude='*.symvers' --exclude='*.mod.c' --exclude='*.ko' v4l-dvb-7c0b887911cf/linux/drivers/media/video/cx18/cx18-av-core.c patched/linux/drivers/media/video/cx18/cx18-av-core.c
--- v4l-dvb-7c0b887911cf/linux/drivers/media/video/cx18/cx18-av-core.c	2010-04-05 22:56:43.000000000 -0400
+++ patched/linux/drivers/media/video/cx18/cx18-av-core.c	2010-04-10 17:10:13.618719139 -0400
@@ -525,6 +525,10 @@
 	cx18_av_and_or(cx, 0x401, ~0x60, 0);
 	cx18_av_and_or(cx, 0x401, ~0x60, 0x60);
 
+	/* assert soft reset of audio */
+	v = cx18_av_read(cx, CXADEC_AUDIO_SOFT_RESET) | 0x01;
+	cx18_av_write_expect(cx, CXADEC_AUDIO_SOFT_RESET, v, v, 0x0f);
+
 	if (std & V4L2_STD_525_60) {
 		if (std == V4L2_STD_NTSC_M_JP) {
 			/* Japan uses EIAJ audio standard */
@@ -549,14 +553,9 @@
 		cx18_av_write_expect(cx, 0x80b, 0x03, 0x03, 0x3f);
 	}
 
-	v = cx18_av_read(cx, 0x803);
-	if (v & 0x10) {
-		/* restart audio decoder microcontroller */
-		v &= ~0x10;
-		cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
-		v |= 0x10;
-		cx18_av_write_expect(cx, 0x803, v, v, 0x1f);
-	}
+	/* deassert soft reset of audio */
+	v = cx18_av_read(cx, CXADEC_AUDIO_SOFT_RESET) & ~0x01;
+	cx18_av_write_expect(cx, CXADEC_AUDIO_SOFT_RESET, v, v, 0x0f);
 }
 
 static int cx18_av_s_frequency(struct v4l2_subdev *sd,
diff -u --recursive --new-file --exclude='.*' --exclude='*.[osa]' --exclude=System.map --exclude='*.orig' --exclude='*.lds' --exclude='*.symvers' --exclude='*.mod.c' --exclude='*.ko' v4l-dvb-7c0b887911cf/linux/drivers/media/video/cx18/cx18-av-core.h patched/linux/drivers/media/video/cx18/cx18-av-core.h
--- v4l-dvb-7c0b887911cf/linux/drivers/media/video/cx18/cx18-av-core.h	2010-04-05 22:56:43.000000000 -0400
+++ patched/linux/drivers/media/video/cx18/cx18-av-core.h	2010-04-10 17:09:26.532890773 -0400
@@ -246,6 +246,7 @@
 
 #define CXADEC_DW8051_INT          0x80C
 #define CXADEC_GENERAL_CTL         0x810
+#define CXADEC_AUDIO_SOFT_RESET    0x810  /* 0x810 or 0x9cc ??? */
 #define CXADEC_AAGC_CTL            0x814
 #define CXADEC_IF_SRC_CTL          0x818
 #define CXADEC_ANLOG_DEMOD_CTL     0x81C
diff -u --recursive --new-file --exclude='.*' --exclude='*.[osa]' --exclude=System.map --exclude='*.orig' --exclude='*.lds' --exclude='*.symvers' --exclude='*.mod.c' --exclude='*.ko' v4l-dvb-7c0b887911cf/linux/drivers/media/video/cx18/cx18-av-firmware.c patched/linux/drivers/media/video/cx18/cx18-av-firmware.c
--- v4l-dvb-7c0b887911cf/linux/drivers/media/video/cx18/cx18-av-firmware.c	2010-04-05 22:56:43.000000000 -0400
+++ patched/linux/drivers/media/video/cx18/cx18-av-firmware.c	2010-03-13 22:06:55.000000000 -0500
@@ -142,14 +142,20 @@
 		return -EIO;
 	}
 
+	/* Disable firmware upload, keeping the 8051 in reset */
 	cx18_av_write4_expect(cx, CXADEC_DL_CTL,
 				0x03000000 | fw->size, 0x03000000, 0x13000000);
 
 	CX18_INFO_DEV(sd, "loaded %s firmware (%d bytes)\n", FWFILE, size);
 
-	if (cx18_av_verifyfw(cx, fw) == 0)
+	if (cx18_av_verifyfw(cx, fw) == 0) {
+		/* deassert soft reset */
+		v = cx18_av_read4(cx, CXADEC_AUDIO_SOFT_RESET) & ~0x01;
+		cx18_av_write4_expect(cx, CXADEC_AUDIO_SOFT_RESET, v, v, 0x0f);
+		/* deassert 8051 reset */
 		cx18_av_write4_expect(cx, CXADEC_DL_CTL,
 				0x13000000 | fw->size, 0x13000000, 0x13000000);
+	}
 
 	/* Output to the 416 */
 	cx18_av_and_or4(cx, CXADEC_PIN_CTRL1, ~0, 0x78000);