V4L/DVB: ivtv: Add firmare monitoring and debug mode to ignore firmware problems

>From Ian's e-mail:
When a device is opened the firmware state will be checked. If it isn't
responding then the open will fail with -EIO.  Due to the nature of the
hardware, a single failed check will block everything since we don't know
exactly what has failed. A side effect of this is the blocking of debug
access, so an additional debug level has been created which allows the block
to be bypassed.

Andy Walls' modifications:
I modified Ian's patch to add a separate fw_debug module parameter to change
the driver's behavior, as opposed to using the normal debug module parameter.
The fw_debug module parameter is only available when CONFIG_VIDEO_ADV_DEBUG
is set.
I also made some minor whitespace adjustments and changed some warning
messages to be a bit more specific.  s/happy/glad/g
Signed-off-by: NIan Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: NAndy Walls <awalls@md.metrocast.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/ivtv/ivtv-driver.c

@@ -130,6 +130,9 @@ static int ivtv_yuv_threshold = -1;
 static int ivtv_pci_latency = 1;
 
 int ivtv_debug;
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+int ivtv_fw_debug;
+#endif
 
 static int tunertype = -1;
 static int newi2c = -1;
@@ -141,6 +144,9 @@ module_param_string(pal, pal, sizeof(pal), 0644);
 module_param_string(secam, secam, sizeof(secam), 0644);
 module_param_string(ntsc, ntsc, sizeof(ntsc), 0644);
 module_param_named(debug,ivtv_debug, int, 0644);
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+module_param_named(fw_debug, ivtv_fw_debug, int, 0644);
+#endif
 module_param(ivtv_pci_latency, int, 0644);
 module_param(ivtv_yuv_mode, int, 0644);
 module_param(ivtv_yuv_threshold, int, 0644);
@@ -217,6 +223,10 @@ MODULE_PARM_DESC(debug,
 		 "\t\t\t 256/0x0100: yuv\n"
 		 "\t\t\t 512/0x0200: i2c\n"
 		 "\t\t\t1024/0x0400: high volume\n");
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+MODULE_PARM_DESC(fw_debug,
+		 "Enable code for debugging firmware problems.  Default: 0\n");
+#endif
 MODULE_PARM_DESC(ivtv_pci_latency,
 		 "Change the PCI latency to 64 if lower: 0 = No, 1 = Yes,\n"
 		 "\t\t\tDefault: Yes");
@@ -1425,6 +1435,9 @@ EXPORT_SYMBOL(ivtv_vapi);
 EXPORT_SYMBOL(ivtv_vapi_result);
 EXPORT_SYMBOL(ivtv_clear_irq_mask);
 EXPORT_SYMBOL(ivtv_debug);
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+EXPORT_SYMBOL(ivtv_fw_debug);
+#endif
 EXPORT_SYMBOL(ivtv_reset_ir_gpio);
 EXPORT_SYMBOL(ivtv_udma_setup);
 EXPORT_SYMBOL(ivtv_udma_unmap);

drivers/media/video/ivtv/ivtv-driver.h

@@ -122,6 +122,9 @@
 
 /* debugging */
 extern int ivtv_debug;
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+extern int ivtv_fw_debug;
+#endif
 
 #define IVTV_DBGFLG_WARN    (1 << 0)
 #define IVTV_DBGFLG_INFO    (1 << 1)

drivers/media/video/ivtv/ivtv-fileops.c

@@ -32,6 +32,7 @@
 #include "ivtv-yuv.h"
 #include "ivtv-ioctl.h"
 #include "ivtv-cards.h"
+#include "ivtv-firmware.h"
 #include <media/v4l2-event.h>
 #include <media/saa7115.h>
 
@@ -526,6 +527,7 @@ int ivtv_start_decoding(struct ivtv_open_id *id, int speed)
 {
 	struct ivtv *itv = id->itv;
 	struct ivtv_stream *s = &itv->streams[id->type];
+	int rc;
 
 	if (atomic_read(&itv->decoding) == 0) {
 		if (ivtv_claim_stream(id, s->type)) {
@@ -533,7 +535,9 @@ int ivtv_start_decoding(struct ivtv_open_id *id, int speed)
 			IVTV_DEBUG_WARN("start decode, stream already claimed\n");
 			return -EBUSY;
 		}
-		ivtv_start_v4l2_decode_stream(s, 0);
+		rc = ivtv_start_v4l2_decode_stream(s, 0);
+		if (rc < 0)
+			return rc;
 	}
 	if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
 		return ivtv_set_speed(itv, speed);
@@ -912,12 +916,30 @@ int ivtv_v4l2_close(struct file *filp)
 
 static int ivtv_serialized_open(struct ivtv_stream *s, struct file *filp)
 {
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	struct video_device *vdev = video_devdata(filp);
+#endif
 	struct ivtv *itv = s->itv;
 	struct ivtv_open_id *item;
 	int res = 0;
 
 	IVTV_DEBUG_FILE("open %s\n", s->name);
 
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	if (ivtv_fw_debug) {
+		IVTV_WARN("Opening %s with dead firmware lockout disabled\n",
+			  video_device_node_name(vdev));
+		IVTV_WARN("Selected firmware errors will be ignored\n");
+	}
+
+	/* Unless ivtv_fw_debug is set, error out if firmware dead. */
+	if (ivtv_firmware_check(itv, "ivtv_serialized_open") && !ivtv_fw_debug)
+		return -EIO;
+#else
+	if (ivtv_firmware_check(itv, "ivtv_serialized_open"))
+		return -EIO;
+#endif
+
 	if (s->type == IVTV_DEC_STREAM_TYPE_MPG &&
 		test_bit(IVTV_F_S_CLAIMED, &itv->streams[IVTV_DEC_STREAM_TYPE_YUV].s_flags))
 		return -EBUSY;

drivers/media/video/ivtv/ivtv-firmware.c

@@ -271,3 +271,49 @@ void ivtv_init_mpeg_decoder(struct ivtv *itv)
 	}
 	ivtv_vapi(itv, CX2341X_DEC_STOP_PLAYBACK, 4, 0, 0, 0, 1);
 }
+
+/* Check firmware running state. The checks fall through
+   allowing multiple failures to be logged. */
+int ivtv_firmware_check(struct ivtv *itv, char *where)
+{
+	int res = 0;
+
+	/* Check encoder is still running */
+	if (ivtv_vapi(itv, CX2341X_ENC_PING_FW, 0) < 0) {
+		IVTV_WARN("Encoder has died : %s\n", where);
+		res = -1;
+	}
+
+	/* Also check audio. Only check if not in use & encoder is okay */
+	if (!res && !atomic_read(&itv->capturing) &&
+	    (!atomic_read(&itv->decoding) ||
+	     (atomic_read(&itv->decoding) < 2 && test_bit(IVTV_F_I_DEC_YUV,
+							     &itv->i_flags)))) {
+
+		if (ivtv_vapi(itv, CX2341X_ENC_MISC, 1, 12) < 0) {
+			IVTV_WARN("Audio has died (Encoder OK) : %s\n", where);
+			res = -2;
+		}
+	}
+
+	if (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT) {
+		/* Second audio check. Skip if audio already failed */
+		if (res != -2 && read_dec(0x100) != read_dec(0x104)) {
+			/* Wait & try again to be certain. */
+			ivtv_msleep_timeout(14, 0);
+			if (read_dec(0x100) != read_dec(0x104)) {
+				IVTV_WARN("Audio has died (Decoder) : %s\n",
+					  where);
+				res = -1;
+			}
+		}
+
+		/* Check decoder is still running */
+		if (ivtv_vapi(itv, CX2341X_DEC_PING_FW, 0) < 0) {
+			IVTV_WARN("Decoder has died : %s\n", where);
+			res = -1;
+		}
+	}
+
+	return res;
+}

drivers/media/video/ivtv/ivtv-firmware.h

@@ -26,5 +26,6 @@ int ivtv_firmware_init(struct ivtv *itv);
 void ivtv_firmware_versions(struct ivtv *itv);
 void ivtv_halt_firmware(struct ivtv *itv);
 void ivtv_init_mpeg_decoder(struct ivtv *itv);
+int ivtv_firmware_check(struct ivtv *itv, char *where);
 
 #endif

drivers/media/video/ivtv/ivtv-streams.c

@@ -42,6 +42,7 @@
 #include "ivtv-yuv.h"
 #include "ivtv-cards.h"
 #include "ivtv-streams.h"
+#include "ivtv-firmware.h"
 #include <media/v4l2-event.h>
 
 static const struct v4l2_file_operations ivtv_v4l2_enc_fops = {
@@ -674,12 +675,17 @@ static int ivtv_setup_v4l2_decode_stream(struct ivtv_stream *s)
 	/* Decoder sometimes dies here, so wait a moment */
 	ivtv_msleep_timeout(10, 0);
 
+	/* Known failure point for firmware, so check */
+	if (ivtv_firmware_check(itv, "ivtv_setup_v4l2_decode_stream") < 0)
+		return -EIO;
+
 	return 0;
 }
 
 int ivtv_start_v4l2_decode_stream(struct ivtv_stream *s, int gop_offset)
 {
 	struct ivtv *itv = s->itv;
+	int rc;
 
 	if (s->vdev == NULL)
 		return -EINVAL;
@@ -689,7 +695,11 @@ int ivtv_start_v4l2_decode_stream(struct ivtv_stream *s, int gop_offset)
 
 	IVTV_DEBUG_INFO("Starting decode stream %s (gop_offset %d)\n", s->name, gop_offset);
 
-	ivtv_setup_v4l2_decode_stream(s);
+	rc = ivtv_setup_v4l2_decode_stream(s);
+	if (rc < 0) {
+		clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
+		return rc;
+	}
 
 	/* set dma size to 65536 bytes */
 	ivtv_vapi(itv, CX2341X_DEC_SET_DMA_BLOCK_SIZE, 1, 65536);