[media] saa7164: allow DMA engine buffers to vary in size between analog and digital
authorSteven Toth <stoth@kernellabs.com>
Sat, 31 Jul 2010 19:01:00 +0000 (16:01 -0300)
committerMauro Carvalho Chehab <mchehab@redhat.com>
Thu, 21 Oct 2010 09:55:01 +0000 (07:55 -0200)
Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
drivers/media/video/saa7164/saa7164-buffer.c
drivers/media/video/saa7164/saa7164-core.c
drivers/media/video/saa7164/saa7164-encoder.c
drivers/media/video/saa7164/saa7164.h

index 5f45ea7f3d7cd2a4ad4e95878a22eb366729640f..187e3f60fa5ac074a941a49162a9d0d3ce5b8bb2 100644 (file)
@@ -134,18 +134,19 @@ struct saa7164_buffer *saa7164_buffer_alloc(struct saa7164_port *port,
        buf->crc = crc32(0, buf->cpu, buf->actual_size);
        memset_io(buf->pt_cpu, 0xff, buf->pt_size);
 
-       dprintk(DBGLVL_BUF, "%s()   allocated buffer @ 0x%p\n",
-               __func__, buf);
+       dprintk(DBGLVL_BUF, "%s()   allocated buffer @ 0x%p (%d pageptrs)\n",
+               __func__, buf, params->numpagetables);
        dprintk(DBGLVL_BUF, "  pci_cpu @ 0x%p    dma @ 0x%08lx len = 0x%x\n",
                buf->cpu, (long)buf->dma, buf->pci_size);
        dprintk(DBGLVL_BUF, "   pt_cpu @ 0x%p pt_dma @ 0x%08lx len = 0x%x\n",
                buf->pt_cpu, (long)buf->pt_dma, buf->pt_size);
 
        /* Format the Page Table Entries to point into the data buffer */
-//     for (i = 0 ; i < SAA7164_PT_ENTRIES; i++) {
-       for (i = 0 ; i < 10; i++) {
+       for (i = 0 ; i < params->numpagetables; i++) {
 
                *(buf->pt_cpu + i) = buf->dma + (i * 0x1000); /* TODO */
+               dprintk(DBGLVL_BUF, "    pt[%02d] = 0x%p -> 0x%llx\n",
+                       i, buf->pt_cpu, (u64)*(buf->pt_cpu));
 
        }
 
index b54b032d56b695a23c5f43c05e0321986dffb019..8879517d974a52fec133bf3e1b71fcd6c67a21af 100644 (file)
@@ -65,6 +65,14 @@ unsigned int print_histogram = 64;
 module_param(print_histogram, int, 0644);
 MODULE_PARM_DESC(print_histogram, "print histogram values once");
 
+unsigned int crc_checking = 1;
+module_param(crc_checking, int, 0644);
+MODULE_PARM_DESC(crc_checking, "enable crc sanity checking on buffers");
+
+unsigned int guard_checking = 1;
+module_param(guard_checking, int, 0644);
+MODULE_PARM_DESC(guard_checking, "enable dma sanity checking for buffer overruns");
+
 static unsigned int saa7164_devcount;
 
 static DEFINE_MUTEX(devlist);
@@ -101,17 +109,24 @@ static void saa7164_pack_verifier(struct saa7164_buffer *buf)
 
        for (i = 0; i < buf->actual_size; i += 2048) {
 
-               if ( (*(p + i + 0) != 0x00) || (*(p + i + 1) != 0x00) || (*(p + i + 2) != 0x01) || (*(p + i + 3) != 0xBA) )
+               if ( (*(p + i + 0) != 0x00) || (*(p + i + 1) != 0x00) ||
+                       (*(p + i + 2) != 0x01) || (*(p + i + 3) != 0xBA) ) {
                        printk(KERN_ERR "No pack at 0x%x\n", i);
+//                     saa7164_dumphex16FF(buf->port->dev, (p + i), 32);
+               }
        }
 }
 
+#define FIXED_VIDEO_PID 0xf1
+#define FIXED_AUDIO_PID 0xf2
+
 static void saa7164_ts_verifier(struct saa7164_buffer *buf)
 {
        struct saa7164_port *port = buf->port;
        u32 i;
-       u8 tmp, cc, a;
-       u8 *bufcpu = (u8 *)buf->cpu;
+       u8 cc, a;
+       u16 pid;
+       u8 __iomem *bufcpu = (u8 *)buf->cpu;
 
        port->sync_errors = 0;
        port->v_cc_errors = 0;
@@ -121,23 +136,25 @@ static void saa7164_ts_verifier(struct saa7164_buffer *buf)
                if (*(bufcpu + i) != 0x47)
                        port->sync_errors++;
 
-               /* Query pid lower 8 bits */
-               tmp = *(bufcpu + i + 2);
+               /* TODO: Query pid lower 8 bits, ignoring upper bits intensionally */
+               pid = ((*(bufcpu + i + 1) & 0x1f) << 8) | *(bufcpu + i + 2);
                cc = *(bufcpu + i + 3) & 0x0f;
 
-               if (tmp == 0xf1) {
+               if (pid == FIXED_VIDEO_PID) {
                        a = ((port->last_v_cc + 1) & 0x0f);
                        if (a != cc) {
-                               printk(KERN_ERR "video cc last = %x current = %x i = %d\n", port->last_v_cc, cc, i);
+                               printk(KERN_ERR "video cc last = %x current = %x i = %d\n",
+                                       port->last_v_cc, cc, i);
                                port->v_cc_errors++;
                        }
 
                        port->last_v_cc = cc;
                } else
-               if (tmp == 0xf2) {
+               if (pid == FIXED_AUDIO_PID) {
                        a = ((port->last_a_cc + 1) & 0x0f);
                        if (a != cc) {
-                               printk(KERN_ERR "audio cc last = %x current = %x i = %d\n", port->last_a_cc, cc, i);
+                               printk(KERN_ERR "audio cc last = %x current = %x i = %d\n",
+                                       port->last_a_cc, cc, i);
                                port->a_cc_errors++;
                        }
 
@@ -246,6 +263,7 @@ static void saa7164_work_enchandler_helper(struct saa7164_port *port, int bufnr)
        struct saa7164_user_buffer *ubuf = 0;
        struct list_head *c, *n;
        int i = 0;
+       u8 __iomem *p;
 
        mutex_lock(&port->dmaqueue_lock);
        list_for_each_safe(c, n, &port->dmaqueue.list) {
@@ -260,12 +278,33 @@ static void saa7164_work_enchandler_helper(struct saa7164_port *port, int bufnr)
                if (buf->idx == bufnr) {
 
                        /* Found the buffer, deal with it */
-                       dprintk(DBGLVL_IRQ, "%s() rp: %d\n", __func__, bufnr);
+                       dprintk(DBGLVL_IRQ, "%s() bufnr: %d\n", __func__, bufnr);
+
+                       if (crc_checking) {
+                               /* Throw a new checksum on the dma buffer */
+                               buf->crc = crc32(0, buf->cpu, buf->actual_size);
+                       }
+
+                       if (guard_checking) {
+                               p = (u8 *)buf->cpu;
+                               if ( (*(p + buf->actual_size + 0) != 0xff) ||
+                                       (*(p + buf->actual_size + 1) != 0xff) ||
+                                       (*(p + buf->actual_size + 2) != 0xff) ||
+                                       (*(p + buf->actual_size + 3) != 0xff) ||
+                                       (*(p + buf->actual_size + 0x10) != 0xff) ||
+                                       (*(p + buf->actual_size + 0x11) != 0xff) ||
+                                       (*(p + buf->actual_size + 0x12) != 0xff) ||
+                                       (*(p + buf->actual_size + 0x13) != 0xff) ) {
+                                               printk(KERN_ERR "%s() buf %p guard buffer breach\n",
+                                                       __func__, buf);
+//                                             saa7164_dumphex16FF(dev, (p + buf->actual_size) - 32 , 64);
+                               }
+                       }
 
                        /* Validate the incoming buffer content */
                        if (port->encoder_params.stream_type == V4L2_MPEG_STREAM_TYPE_MPEG2_TS)
                                saa7164_ts_verifier(buf);
-                       if (port->encoder_params.stream_type == V4L2_MPEG_STREAM_TYPE_MPEG2_PS)
+                       else if (port->encoder_params.stream_type == V4L2_MPEG_STREAM_TYPE_MPEG2_PS)
                                saa7164_pack_verifier(buf);
 
                        /* find a free user buffer and clone to it */
@@ -280,8 +319,10 @@ static void saa7164_work_enchandler_helper(struct saa7164_port *port, int bufnr)
                                        memcpy_fromio(ubuf->data, buf->cpu,
                                                ubuf->actual_size);
 
-                                       /* Throw a new checksum on the read buffer */
-                                       ubuf->crc = crc32(0, ubuf->data, ubuf->actual_size);
+                                       if (crc_checking) {
+                                               /* Throw a new checksum on the read buffer */
+                                               ubuf->crc = crc32(0, ubuf->data, ubuf->actual_size);
+                                       }
 
                                        /* Requeue the buffer on the free list */
                                        ubuf->pos = 0;
@@ -304,6 +345,10 @@ static void saa7164_work_enchandler_helper(struct saa7164_port *port, int bufnr)
                         * in time. */
                        saa7164_buffer_zero_offsets(port, bufnr);
                        memset_io(buf->cpu, 0xff, buf->pci_size);
+                       if (crc_checking) {
+                               /* Throw yet aanother new checksum on the dma buffer */
+                               buf->crc = crc32(0, buf->cpu, buf->actual_size);
+                       }
 
                        break;
                }
@@ -352,17 +397,22 @@ static void saa7164_work_enchandler(struct work_struct *w)
 
        /* Most current complete buffer */
        if (wp == 0)
-               mcb = 7;
+               mcb = (port->hwcfg.buffercount - 1);
        else
                mcb = wp - 1;
 
        while (1) {
-               rp = (port->last_svc_rp + 1) % 8;
+               if (port->done_first_interrupt == 0) {
+                       port->done_first_interrupt++;
+                       rp = mcb;
+               } else
+                       rp = (port->last_svc_rp + 1) % 8;
 
-               if ((rp < 0) || (rp > 7)) {
+               if ((rp < 0) || (rp > (port->hwcfg.buffercount - 1))) {
                        printk(KERN_ERR "%s() illegal rp count %d\n", __func__, rp);
                        break;
                }
+
                saa7164_work_enchandler_helper(port, rp);
                port->last_svc_rp = rp;
                cnt++;
@@ -371,6 +421,7 @@ static void saa7164_work_enchandler(struct work_struct *w)
                        break;
        }
 
+       /* TODO: Convert this into a /proc/saa7164 style readable file */
        if (print_histogram == port->nr) {
                saa7164_histogram_print(port, &port->irq_interval);
                saa7164_histogram_print(port, &port->svc_interval);
@@ -438,7 +489,7 @@ static irqreturn_t saa7164_irq_ts(struct saa7164_port *port)
 
        /* Find the previous buffer to the current write point */
        if (wp == 0)
-               rp = 7;
+               rp = (port->hwcfg.buffercount - 1);
        else
                rp = wp - 1;
 
index 08b62e41c466690a91c5ffe139feb1e2bfeacea0..0859448bae050b6187b96fa86696272787d77999 100644 (file)
@@ -76,15 +76,131 @@ static void saa7164_encoder_configure(struct saa7164_port *port)
        saa7164_api_set_audio_std(port);
 }
 
-/* One time configuration at registration time */
-static int saa7164_encoder_initialize(struct saa7164_port *port)
+static int saa7164_encoder_buffers_dealloc(struct saa7164_port *port)
+{
+       struct list_head *c, *n, *p, *q, *l, *v;
+       struct saa7164_dev *dev = port->dev;
+       struct saa7164_buffer *buf;
+       struct saa7164_user_buffer *ubuf;
+
+       /* Remove any allocated buffers */
+       mutex_lock(&port->dmaqueue_lock);
+
+       dprintk(DBGLVL_ENC, "%s(port=%d) dmaqueue\n", __func__, port->nr);
+       list_for_each_safe(c, n, &port->dmaqueue.list) {
+               buf = list_entry(c, struct saa7164_buffer, list);
+               list_del(c);
+               saa7164_buffer_dealloc(buf);
+       }
+
+       dprintk(DBGLVL_ENC, "%s(port=%d) used\n", __func__, port->nr);
+       list_for_each_safe(p, q, &port->list_buf_used.list) {
+               ubuf = list_entry(p, struct saa7164_user_buffer, list);
+               list_del(p);
+               saa7164_buffer_dealloc_user(ubuf);
+       }
+
+       dprintk(DBGLVL_ENC, "%s(port=%d) free\n", __func__, port->nr);
+       list_for_each_safe(l, v, &port->list_buf_free.list) {
+               ubuf = list_entry(l, struct saa7164_user_buffer, list);
+               list_del(l);
+               saa7164_buffer_dealloc_user(ubuf);
+       }
+
+       mutex_unlock(&port->dmaqueue_lock);
+       dprintk(DBGLVL_ENC, "%s(port=%d) done\n", __func__, port->nr);
+
+       return 0;
+}
+
+/* Dynamic buffer switch at encoder start time */
+static int saa7164_encoder_buffers_alloc(struct saa7164_port *port)
 {
        struct saa7164_dev *dev = port->dev;
+       struct saa7164_buffer *buf;
+       struct saa7164_user_buffer *ubuf;
+       tmHWStreamParameters_t *params = &port->hw_streamingparams;
+       int result = -ENODEV, i;
+       int len = 0;
 
        dprintk(DBGLVL_ENC, "%s()\n", __func__);
 
-       saa7164_encoder_configure(port);
+       if (port->encoder_params.stream_type == V4L2_MPEG_STREAM_TYPE_MPEG2_PS) {
+               dprintk(DBGLVL_ENC, "%s() type=V4L2_MPEG_STREAM_TYPE_MPEG2_PS\n", __func__);
+               params->samplesperline = 128;
+               params->numberoflines = 256;
+               params->pitch = 128;
+               params->numpagetables = 2 +
+                       ((SAA7164_PS_NUMBER_OF_LINES * 128) / PAGE_SIZE);
+       } else
+       if (port->encoder_params.stream_type == V4L2_MPEG_STREAM_TYPE_MPEG2_TS) {
+               dprintk(DBGLVL_ENC, "%s() type=V4L2_MPEG_STREAM_TYPE_MPEG2_TS\n", __func__);
+               params->samplesperline = 188;
+               params->numberoflines = 312;
+               params->pitch = 188;
+               params->numpagetables = 2 +
+                       ((SAA7164_TS_NUMBER_OF_LINES * 188) / PAGE_SIZE);
+       } else
+               BUG();
+
+       /* Init and establish defaults */
+       params->bitspersample = 8;
+       params->linethreshold = 0;
+       params->pagetablelistvirt = 0;
+       params->pagetablelistphys = 0;
+       params->numpagetableentries = port->hwcfg.buffercount;
+
+       /* Allocate the PCI resources, buffers (hard) */
+       for (i = 0; i < port->hwcfg.buffercount; i++) {
+               buf = saa7164_buffer_alloc(port,
+                       params->numberoflines *
+                       params->pitch);
+
+               if (!buf) {
+                       printk(KERN_ERR "%s() failed "
+                              "(errno = %d), unable to allocate buffer\n",
+                               __func__, result);
+                       result = -ENOMEM;
+                       goto failed;
+               } else {
+
+                       mutex_lock(&port->dmaqueue_lock);
+                       list_add_tail(&buf->list, &port->dmaqueue.list);
+                       mutex_unlock(&port->dmaqueue_lock);
+
+               }
+       }
+
+       /* Allocate some kenrel kernel buffers for copying
+        * to userpsace.
+        */
+       len = params->numberoflines * params->pitch;
+
+       if (encoder_buffers < 16)
+               encoder_buffers = 16;
+       if (encoder_buffers > 512)
+               encoder_buffers = 512;
+
+       for (i = 0; i < encoder_buffers; i++) {
+
+               ubuf = saa7164_buffer_alloc_user(dev, len);
+               if (ubuf) {
+                       mutex_lock(&port->dmaqueue_lock);
+                       list_add_tail(&ubuf->list, &port->list_buf_free.list);
+                       mutex_unlock(&port->dmaqueue_lock);
+               }
+
+       }
+
+       result = 0;
 
+failed:
+       return result;
+}
+
+static int saa7164_encoder_initialize(struct saa7164_port *port)
+{
+       saa7164_encoder_configure(port);
        return 0;
 }
 
@@ -835,6 +951,7 @@ static int saa7164_encoder_stop_streaming(struct saa7164_port *port)
        dprintk(DBGLVL_ENC, "%s(port=%d) Hardware stopped\n", __func__,
                port->nr);
 
+       /* Reset the state of any allocated buffer resources */
        mutex_lock(&port->dmaqueue_lock);
 
        /* Reset the hard and soft buffer state */
@@ -851,6 +968,10 @@ static int saa7164_encoder_stop_streaming(struct saa7164_port *port)
        }
 
        mutex_unlock(&port->dmaqueue_lock);
+
+       /* Free any allocated resources */
+       saa7164_encoder_buffers_dealloc(port);
+
        dprintk(DBGLVL_ENC, "%s(port=%d) Released\n", __func__, port->nr);
 
        return ret;
@@ -863,10 +984,19 @@ static int saa7164_encoder_start_streaming(struct saa7164_port *port)
 
        dprintk(DBGLVL_ENC, "%s(port=%d)\n", __func__, port->nr);
 
+       port->done_first_interrupt = 0;
+
+       /* allocate all of the PCIe DMA buffer resources on the fly,
+        * allowing switching between TS and PS payloads without
+        * requiring a complete driver reload.
+        */
+       saa7164_encoder_buffers_alloc(port);
+
        /* Configure the encoder with any cache values */
        saa7164_api_set_encoder(port);
        saa7164_api_get_encoder(port);
 
+       /* Place the empty buffers on the hardware */
        saa7164_buffer_cfg_port(port);
 
        /* Acquire the hardware */
@@ -1005,27 +1135,29 @@ static int fops_release(struct file *file)
 
 struct saa7164_user_buffer *saa7164_enc_next_buf(struct saa7164_port *port)
 {
-       struct saa7164_user_buffer *buf = 0;
+       struct saa7164_user_buffer *ubuf = 0;
        struct saa7164_dev *dev = port->dev;
        u32 crc;
 
        mutex_lock(&port->dmaqueue_lock);
        if (!list_empty(&port->list_buf_used.list)) {
-               buf = list_first_entry(&port->list_buf_used.list,
+               ubuf = list_first_entry(&port->list_buf_used.list,
                        struct saa7164_user_buffer, list);
 
-               crc = crc32(0, buf->data, buf->actual_size);
-               if (crc != buf->crc) {
-                       printk(KERN_ERR "%s() buf %p crc became invalid, was 0x%x became 0x%x\n", __func__,
-                               buf, buf->crc, crc);
+               if (crc_checking) {
+                       crc = crc32(0, ubuf->data, ubuf->actual_size);
+                       if (crc != ubuf->crc) {
+                               printk(KERN_ERR "%s() ubuf %p crc became invalid, was 0x%x became 0x%x\n", __func__,
+                                       ubuf, ubuf->crc, crc);
+                       }
                }
 
        }
        mutex_unlock(&port->dmaqueue_lock);
 
-       dprintk(DBGLVL_ENC, "%s() returns %p\n", __func__, buf);
+       dprintk(DBGLVL_ENC, "%s() returns %p\n", __func__, ubuf);
 
-       return buf;
+       return ubuf;
 }
 
 static ssize_t fops_read(struct file *file, char __user *buffer,
@@ -1292,10 +1424,7 @@ static struct video_device *saa7164_encoder_alloc(
 int saa7164_encoder_register(struct saa7164_port *port)
 {
        struct saa7164_dev *dev = port->dev;
-       struct saa7164_buffer *buf;
-       struct saa7164_user_buffer *ubuf;
-       int result = -ENODEV, i;
-       int len = 0;
+       int result = -ENODEV;
 
        dprintk(DBGLVL_ENC, "%s()\n", __func__);
 
@@ -1311,64 +1440,6 @@ int saa7164_encoder_register(struct saa7164_port *port)
                goto failed;
        }
 
-       /* Init and establish defaults */
-       /* TODO: Check the umber of lines for PS */
-       port->hw_streamingparams.bitspersample = 8;
-       port->hw_streamingparams.samplesperline = 128;
-       port->hw_streamingparams.numberoflines = 256;
-
-       port->hw_streamingparams.pitch = 128;
-       port->hw_streamingparams.linethreshold = 0;
-       port->hw_streamingparams.pagetablelistvirt = 0;
-       port->hw_streamingparams.pagetablelistphys = 0;
-       port->hw_streamingparams.numpagetables = 2 +
-               ((SAA7164_PS_NUMBER_OF_LINES * 128) / PAGE_SIZE);
-
-       port->hw_streamingparams.numpagetableentries = port->hwcfg.buffercount;
-
-       /* Allocate the PCI resources, buffers (hard) */
-       for (i = 0; i < port->hwcfg.buffercount; i++) {
-               buf = saa7164_buffer_alloc(port,
-                       port->hw_streamingparams.numberoflines *
-                       port->hw_streamingparams.pitch);
-
-               if (!buf) {
-                       printk(KERN_ERR "%s() failed "
-                              "(errno = %d), unable to allocate buffer\n",
-                               __func__, result);
-                       result = -ENOMEM;
-                       goto failed;
-               } else {
-
-                       mutex_lock(&port->dmaqueue_lock);
-                       list_add_tail(&buf->list, &port->dmaqueue.list);
-                       mutex_unlock(&port->dmaqueue_lock);
-
-               }
-       }
-
-       /* Allocate some kenrel kernel buffers for copying
-        * to userpsace.
-        */
-       len = port->hw_streamingparams.numberoflines *
-               port->hw_streamingparams.pitch;
-
-       if (encoder_buffers < 16)
-               encoder_buffers = 16;
-       if (encoder_buffers > 512)
-               encoder_buffers = 512;
-
-       for (i = 0; i < encoder_buffers; i++) {
-
-               ubuf = saa7164_buffer_alloc_user(dev, len);
-               if (ubuf) {
-                       mutex_lock(&port->dmaqueue_lock);
-                       list_add_tail(&ubuf->list, &port->list_buf_free.list);
-                       mutex_unlock(&port->dmaqueue_lock);
-               }
-
-       }
-
        /* Establish encoder defaults here */
        /* Set default TV standard */
        port->encodernorm = saa7164_tvnorms[0];
@@ -1446,9 +1517,6 @@ failed:
 void saa7164_encoder_unregister(struct saa7164_port *port)
 {
        struct saa7164_dev *dev = port->dev;
-       struct saa7164_buffer *buf;
-       struct saa7164_user_buffer *ubuf;
-       struct list_head *c, *n, *p, *q, *l, *v;
 
        dprintk(DBGLVL_ENC, "%s(port=%d)\n", __func__, port->nr);
 
@@ -1464,31 +1532,6 @@ void saa7164_encoder_unregister(struct saa7164_port *port)
                port->v4l_device = NULL;
        }
 
-       /* Remove any allocated buffers */
-       mutex_lock(&port->dmaqueue_lock);
-
-       dprintk(DBGLVL_ENC, "%s(port=%d) dmaqueue\n", __func__, port->nr);
-       list_for_each_safe(c, n, &port->dmaqueue.list) {
-               buf = list_entry(c, struct saa7164_buffer, list);
-               list_del(c);
-               saa7164_buffer_dealloc(buf);
-       }
-
-       dprintk(DBGLVL_ENC, "%s(port=%d) used\n", __func__, port->nr);
-       list_for_each_safe(p, q, &port->list_buf_used.list) {
-               ubuf = list_entry(p, struct saa7164_user_buffer, list);
-               list_del(p);
-               saa7164_buffer_dealloc_user(ubuf);
-       }
-
-       dprintk(DBGLVL_ENC, "%s(port=%d) free\n", __func__, port->nr);
-       list_for_each_safe(l, v, &port->list_buf_free.list) {
-               ubuf = list_entry(l, struct saa7164_user_buffer, list);
-               list_del(l);
-               saa7164_buffer_dealloc_user(ubuf);
-       }
-
-       mutex_unlock(&port->dmaqueue_lock);
        dprintk(DBGLVL_ENC, "%s(port=%d) done\n", __func__, port->nr);
 }
 
index 71e385328ce30aec052442dbf80b7512f57a9de0..0cafe8a557e500338c5fe475fc4c38cab018a96e 100644 (file)
@@ -389,6 +389,7 @@ struct saa7164_port {
        u32 a_cc_errors;
        u8 last_v_cc;
        u8 last_a_cc;
+       u32 done_first_interrupt;
 };
 
 struct saa7164_dev {
@@ -546,6 +547,8 @@ void saa7164_encoder_unregister(struct saa7164_port *port);
 
 /* ----------------------------------------------------------- */
 
+extern unsigned int crc_checking;
+
 extern unsigned int saa_debug;
 #define dprintk(level, fmt, arg...)\
        do { if (saa_debug & level)\