V4L/DVB (12823): tm6000: Uses another method for handling incomplete packets

This requires a little more memory, and some memcpy to work, but the logic is
simpler than the previous method.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 129 insertions, 133 deletions

diff --git a/drivers/staging/tm6000/tm6000-regs.h b/drivers/staging/tm6000/tm6000-regs.h
index 3d676fcc262d..85acc07f62e9 100644
--- a/drivers/staging/tm6000/tm6000-regs.h
+++ b/drivers/staging/tm6000/tm6000-regs.h
@@ -77,7 +77,6 @@
  * Define TV Master TM5600/TM6000 URB message codes and length
  */
 
-#define TM6000_URB_MSG_LEN 180
 enum {
         TM6000_URB_MSG_VIDEO=1,
         TM6000_URB_MSG_AUDIO,
diff --git a/drivers/staging/tm6000/tm6000-usb-isoc.h b/drivers/staging/tm6000/tm6000-usb-isoc.h
index 42de91715185..10e72c04f74f 100644
--- a/drivers/staging/tm6000/tm6000-usb-isoc.h
+++ b/drivers/staging/tm6000/tm6000-usb-isoc.h
@@ -19,6 +19,8 @@
 
 #include <linux/videodev2.h>
 
+#define TM6000_URB_MSG_LEN 180
+
 struct usb_isoc_ctl {
                 /* max packet size of isoc transaction */
         int                             max_pkt_size;
@@ -32,16 +34,16 @@ struct usb_isoc_ctl {
                 /* transfer buffers for isoc transfer */
         char                            **transfer_buffer;
 
-                /* Last buffer command and region */
-        u8                              cmd;
-        int                             pos, size, pktsize;
+                /* Last buffer control */
+        int                             pending;
+        int                             pos;
 
                 /* Last field: ODD or EVEN? */
         int                             field;
 
                 /* Stores incomplete commands */
-        u32                             tmp_buf;
-        int                             tmp_buf_len;
+        u8                              tbuf[TM6000_URB_MSG_LEN+4];
+        size_t                          len;
 
                 /* Stores already requested buffers */
         struct tm6000_buffer            *buf;
diff --git a/drivers/staging/tm6000/tm6000-video.c b/drivers/staging/tm6000/tm6000-video.c
index 107d597038b8..b72cfd0d7559 100644
--- a/drivers/staging/tm6000/tm6000-video.c
+++ b/drivers/staging/tm6000/tm6000-video.c
@@ -215,92 +215,83 @@ static int copy_packet (struct urb *urb, u32 header, u8 **ptr, u8 *endp,
          */
         unsigned int linewidth=(*buf)->vb.width<<1;
 
+        c=(header>>24) & 0xff;
+
+        /* split the header fields */
+        size  = (((header & 0x7e)<<1) -1) *4;
+        block = (header>>7) & 0xf;
+        field = (header>>11) & 0x1;
+        line  = (header>>12) & 0x1ff;
+        cmd   = (header>>21) & 0x7;
+
+        /* Validates header fields */
+        if(size>TM6000_URB_MSG_LEN)
+                size = TM6000_URB_MSG_LEN;
+
+        if (cmd == TM6000_URB_MSG_VIDEO) {
+                if ((block+1)*TM6000_URB_MSG_LEN>linewidth)
+                        cmd = TM6000_URB_MSG_ERR;
+
+                /* FIXME: Mounts the image as field0+field1
+                        * It should, instead, check if the user selected
+                        * entrelaced or non-entrelaced mode
+                        */
+                pos= ((line<<1)+field)*linewidth +
+                        block*TM6000_URB_MSG_LEN;
+
+                /* Don't allow to write out of the buffer */
+                if (pos+TM6000_URB_MSG_LEN > (*buf)->vb.size) {
+                        dprintk(dev, V4L2_DEBUG_ISOC,
+                                "ERR: size=%d, num=%d, line=%d, "
+                                "field=%d\n",
+                                size, block, line, field);
 
-        if (!dev->isoc_ctl.cmd) {
-                c=(header>>24) & 0xff;
-
-                /* split the header fields */
-                size  = (((header & 0x7e)<<1) -1) *4;
-                block = (header>>7) & 0xf;
-                field = (header>>11) & 0x1;
-                line  = (header>>12) & 0x1ff;
-                cmd   = (header>>21) & 0x7;
+                        cmd = TM6000_URB_MSG_ERR;
+                }
+        } else {
+                pos=0;
+        }
 
-                /* Validates header fields */
-                if(size>TM6000_URB_MSG_LEN)
-                        size = TM6000_URB_MSG_LEN;
+        /* Prints debug info */
+        dprintk(dev, V4L2_DEBUG_ISOC, "size=%d, num=%d, "
+                        " line=%d, field=%d\n",
+                        size, block, line, field);
+
+        if ((last_line!=line)&&(last_line+1!=line) &&
+                (cmd != TM6000_URB_MSG_ERR) )  {
+                if (cmd != TM6000_URB_MSG_VIDEO)  {
+                        dprintk(dev, V4L2_DEBUG_ISOC,  "cmd=%d, "
+                                "size=%d, num=%d, line=%d, field=%d\n",
+                                cmd, size, block, line, field);
+                }
+                if (start_line<0)
+                        start_line=last_line;
+                /* Prints debug info */
+                dprintk(dev, V4L2_DEBUG_ISOC, "lines= %d-%d, "
+                                "field=%d\n",
+                                start_line, last_line, field);
 
-                if (cmd == TM6000_URB_MSG_VIDEO) {
-                        if ((block+1)*TM6000_URB_MSG_LEN>linewidth)
-                                cmd = TM6000_URB_MSG_ERR;
+                if ((start_line<6 && last_line>200) &&
+                        (last_field != field) ) {
 
-                        /* FIXME: Mounts the image as field0+field1
-                         * It should, instead, check if the user selected
-                         * entrelaced or non-entrelaced mode
-                         */
-                        pos= ((line<<1)+field)*linewidth +
-                                block*TM6000_URB_MSG_LEN;
+                        dev->isoc_ctl.nfields++;
+                        if (dev->isoc_ctl.nfields>=2) {
+                                dev->isoc_ctl.nfields=0;
 
-                        /* Don't allow to write out of the buffer */
-                        if (pos+TM6000_URB_MSG_LEN > (*buf)->vb.size) {
+                                /* Announces that a new buffer were filled */
+                                buffer_filled (dev, dma_q, *buf);
                                 dprintk(dev, V4L2_DEBUG_ISOC,
-                                        "ERR: size=%d, num=%d, line=%d, "
-                                        "field=%d\n",
-                                        size, block, line, field);
-
-                                cmd = TM6000_URB_MSG_ERR;
-                        }
-                } else {
-                        pos=0;
-                }
-
-                /* Prints debug info */
-                dprintk(dev, V4L2_DEBUG_ISOC, "size=%d, num=%d, "
-                                " line=%d, field=%d\n",
-                                size, block, line, field);
-
-                if ((last_line!=line)&&(last_line+1!=line) &&
-                    (cmd != TM6000_URB_MSG_ERR) )  {
-                        if (cmd != TM6000_URB_MSG_VIDEO)  {
-                                dprintk(dev, V4L2_DEBUG_ISOC,  "cmd=%d, "
-                                        "size=%d, num=%d, line=%d, field=%d\n",
-                                        cmd, size, block, line, field);
-                        }
-                        if (start_line<0)
-                                start_line=last_line;
-                        /* Prints debug info */
-                        dprintk(dev, V4L2_DEBUG_ISOC, "lines= %d-%d, "
-                                        "field=%d\n",
-                                        start_line, last_line, field);
-
-                        if ((start_line<6 && last_line>200) &&
-                                (last_field != field) ) {
-
-                                dev->isoc_ctl.nfields++;
-                                if (dev->isoc_ctl.nfields>=2) {
-                                        dev->isoc_ctl.nfields=0;
-
-                                        /* Announces that a new buffer were filled */
-                                        buffer_filled (dev, dma_q, *buf);
-                                        dprintk(dev, V4L2_DEBUG_ISOC,
-                                                        "new buffer filled\n");
-                                        rc=get_next_buf (dma_q, buf);
-                                }
+                                                "new buffer filled\n");
+                                rc=get_next_buf (dma_q, buf);
                         }
-
-                        start_line=line;
-                        last_field=field;
                 }
-                last_line=line;
 
-                pktsize = TM6000_URB_MSG_LEN;
-        } else {
-                /* Continue the last copy */
-                cmd = dev->isoc_ctl.cmd;
-                size= dev->isoc_ctl.size;
-                pos = dev->isoc_ctl.pos;
-                pktsize = dev->isoc_ctl.pktsize;
+                start_line=line;
+                last_field=field;
         }
+        last_line=line;
+
+        pktsize = TM6000_URB_MSG_LEN;
 
         cpysize=(endp-(*ptr)>size)?size:endp-(*ptr);
 
@@ -325,19 +316,7 @@ printk ("%ld: cmd=%s, size=%d\n", jiffies,
                                                 tm6000_msg_type[cmd],size);
                 }
         }
-        if (cpysize<size) {
-                /* End of URB packet, but cmd processing is not
-                 * complete. Preserve the state for a next packet
-                 */
-                dev->isoc_ctl.pos = pos+cpysize;
-                dev->isoc_ctl.size= size-cpysize;
-                dev->isoc_ctl.cmd = cmd;
-                dev->isoc_ctl.pktsize = pktsize-cpysize;
-                (*ptr)+=cpysize;
-        } else {
-                dev->isoc_ctl.cmd = 0;
-                (*ptr)+=pktsize;
-        }
+        (*ptr)+=cpysize;
 
         return rc;
 }
@@ -347,57 +326,73 @@ static int copy_streams(u8 *data, u8 *out_p, unsigned long len,
 {
         struct tm6000_dmaqueue  *dma_q = urb->context;
         struct tm6000_core *dev= container_of(dma_q,struct tm6000_core,vidq);
-        u8 *ptr=data, *endp=data+len;
+        u8 *ptr, *endp;
         unsigned long header=0;
-        int rc=0;
+        int rc=0, size;
 
-        for (ptr=data; ptr<endp;) {
-                if (!dev->isoc_ctl.cmd) {
-                        u8 *p=(u8 *)&dev->isoc_ctl.tmp_buf;
-                        /* FIXME: This seems very complex
-                         * It just recovers up to 3 bytes of the header that
-                         * might be at the previous packet
-                         */
-                        if (dev->isoc_ctl.tmp_buf_len) {
-                                while (dev->isoc_ctl.tmp_buf_len) {
-                                        if ( *(ptr+3-dev->isoc_ctl.tmp_buf_len) == 0x47) {
-                                                break;
-                                        }
-                                        p++;
-                                        dev->isoc_ctl.tmp_buf_len--;
-                                }
-                                if (dev->isoc_ctl.tmp_buf_len) {
-                                        memcpy (&header,p,
-                                                dev->isoc_ctl.tmp_buf_len);
-                                        memcpy (((u8 *)header)+
-                                                dev->isoc_ctl.tmp_buf,
-                                                ptr,
-                                                4-dev->isoc_ctl.tmp_buf_len);
-                                        ptr+=4-dev->isoc_ctl.tmp_buf_len;
-                                        goto HEADER;
-                                }
-                        }
+        /* Process pending data */
+        if (dev->isoc_ctl.pending) {
+                memcpy(dev->isoc_ctl.tbuf + dev->isoc_ctl.len, ptr,
+                       sizeof(dev->isoc_ctl.tbuf) - dev->isoc_ctl.len);
+
+                /* Seek for sync */
+                endp = dev->isoc_ctl.tbuf + sizeof(dev->isoc_ctl.tbuf);
+                for (ptr = dev->isoc_ctl.tbuf;ptr < endp - 3;ptr++) {
+                        if (*(ptr + 3) == 0x47)
+                                break;
+                }
+                header=*(unsigned long *)ptr;
+                size  = (((header & 0x7e) << 1) - 1) * 4;
+                if(size > TM6000_URB_MSG_LEN)
+                        size = TM6000_URB_MSG_LEN;
+
+                if (ptr+3+size >= endp) {
+                        printk(KERN_ERR "tm6000: broken data\n");
+                        ptr = data;
+                        goto process_new_uri;
+                }
+                ptr+=4;
+
+                /* Copy or continue last copy */
+                rc=copy_packet(urb, header, &ptr, endp, out_p, buf);
+                if (rc<0) {
+                        buf=NULL;
+                        printk(KERN_ERR "tm6000: buffer underrun at %ld\n",
+                                        jiffies);
+                        return rc;
+                }
+                dev->isoc_ctl.pending = 0;
+                ptr = data + (ptr - dev->isoc_ctl.tbuf);
+        } else
+                ptr = data;
+
+process_new_uri:
+        endp = data + len;
+        while (ptr<endp) {
+                if (!dev->isoc_ctl.pending) {
                         /* Seek for sync */
                         for (;ptr<endp-3;ptr++) {
                                 if (*(ptr+3)==0x47)
                                         break;
                         }
+                        header=*(unsigned long *)ptr;
+                        size  = (((header & 0x7e)<<1) -1) *4;
+                        if(size>TM6000_URB_MSG_LEN)
+                                size = TM6000_URB_MSG_LEN;
+
+                        if (ptr+3+size >= endp) {
+                                int len = endp - ptr;
 
-                        if (ptr+3>=endp) {
-                                dev->isoc_ctl.tmp_buf_len=endp-ptr;
-                                memcpy (&dev->isoc_ctl.tmp_buf,ptr,
-                                        dev->isoc_ctl.tmp_buf_len);
-                                dev->isoc_ctl.cmd=0;
+                                memcpy (dev->isoc_ctl.tbuf, ptr, len);
+                                dev->isoc_ctl.len = len;
+                                dev->isoc_ctl.pending = 1;
                                 return rc;
                         }
-
-                        /* Get message header */
-                        header=*(unsigned long *)ptr;
                         ptr+=4;
                 }
-HEADER:
+
                 /* Copy or continue last copy */
-                rc=copy_packet(urb,header,&ptr,endp,out_p,buf);
+                rc=copy_packet(urb, header, &ptr, endp, out_p, buf);
                 if (rc<0) {
                         buf=NULL;
                         printk(KERN_ERR "tm6000: buffer underrun at %ld\n",