cmd is now dumping the first 5 packets. They are usually leftovers

from last the cmd: 4 packets from the quad buffer in the usbduxfast
and one packet kept by the host controller.

diff --git a/comedi/drivers/usbduxfast.c b/comedi/drivers/usbduxfast.c
index 7aeb7ec87f90dc325422fd0ccfee3d10d3f34145..e385e3b47a4ab3bbc01d18bc32c2a62d44c00dc9 100644 (file)
--- a/comedi/drivers/usbduxfast.c
+++ b/comedi/drivers/usbduxfast.c
@@ -114,6 +114,11 @@ Status: testing
 // minimal time in nanoseconds between two samples
 #define MIN_SAMPLING_PERIOD 9 // steps at 30MHz in the FX2
 
+// number of received packets to ignore before we start handing data over to comedi
+// 4 packets because of quad buffering and 1 for the host controller side
+#define PACKETS_TO_IGNORE 5
+
+
 /////////////////////////////////////////////
 // comedi constants
 static comedi_lrange range_usbduxfast_ai_range = { 2, {
@@ -161,7 +166,8 @@ typedef struct {
        unsigned int ai_counter;
        // commands
        uint8_t *dux_commands;
-       short int ai_insn_running;
+       // counter which ignores the first buffers
+       int ignore;
        struct semaphore sem;
 } usbduxfastsub_t;
 
@@ -403,39 +409,43 @@ static void usbduxfastsub_ai_IsocIrq(struct urb *urb, struct pt_regs *regs)
        }
 
 
-       // get the data from the USB bus and hand it over
-       // to comedi
-       p=urb->transfer_buffer;
-       if (!(this_usbduxfastsub->ai_continous)) {
-               // not continous, fixed number of samples
-               n=urb->iso_frame_desc[0].actual_length/sizeof(uint16_t);
-               if (unlikely(this_usbduxfastsub->ai_sample_count<n)) {
-                       // we have send only a fraction of the bytes received
-                       cfc_write_array_to_buffer(s,
-                                                 urb->transfer_buffer,
-                                                 this_usbduxfastsub->ai_sample_count*sizeof(uint16_t));
-                       usbduxfast_ai_stop(this_usbduxfastsub,
-                                          0);
-                       // say comedi that the acquistion is over
-                       s->async->events |= COMEDI_CB_EOA;
-                       comedi_event(this_usbduxfastsub->comedidev, 
-                                    s, 
-                                    s->async->events);
-                       return;
+       if (!this_usbduxfastsub->ignore) {
+               // get the data from the USB bus and hand it over
+               // to comedi
+               p=urb->transfer_buffer;
+               if (!(this_usbduxfastsub->ai_continous)) {
+                       // not continous, fixed number of samples
+                       n=urb->iso_frame_desc[0].actual_length/sizeof(uint16_t);
+                       if (unlikely(this_usbduxfastsub->ai_sample_count<n)) {
+                               // we have send only a fraction of the bytes received
+                               cfc_write_array_to_buffer(s,
+                                                         urb->transfer_buffer,
+                                                         this_usbduxfastsub->ai_sample_count*sizeof(uint16_t));
+                               usbduxfast_ai_stop(this_usbduxfastsub,
+                                                  0);
+                               // say comedi that the acquistion is over
+                               s->async->events |= COMEDI_CB_EOA;
+                               comedi_event(this_usbduxfastsub->comedidev, 
+                                            s, 
+                                            s->async->events);
+                               return;
+                       }
+                       this_usbduxfastsub->ai_sample_count-=n;
                }
-               this_usbduxfastsub->ai_sample_count-=n;
-       }
        
-       // write the full buffer to comedi
-       cfc_write_array_to_buffer(s,
-                                 urb->transfer_buffer,
-                                 urb->iso_frame_desc[0].actual_length);
-
-       // tell comedi that data is there
-       comedi_event(this_usbduxfastsub->comedidev, 
-                    s,
-                    s->async->events);
-
+               // write the full buffer to comedi
+               cfc_write_array_to_buffer(s,
+                                         urb->transfer_buffer,
+                                         urb->iso_frame_desc[0].actual_length);
+               
+               // tell comedi that data is there
+               comedi_event(this_usbduxfastsub->comedidev, 
+                            s,
+                            s->async->events);
+       } else {
+               this_usbduxfastsub->ignore--;
+       }
+               
        // command is still running
        // resubmit urb for ISO transfer
        urb->dev = this_usbduxfastsub->usbdev;
@@ -855,12 +865,6 @@ static int usbduxfast_ai_cmd(comedi_device *dev, comedi_subdevice *s)
                up(&this_usbduxfastsub->sem);
                return -ENODEV;
        }
-       if (this_usbduxfastsub->ai_insn_running) {
-               printk("comedi%d: ai_cmd not possible. Sync command is running.\n",
-                      dev->minor);
-               up(&this_usbduxfastsub->sem);
-               return -EBUSY;
-       }       
        if (this_usbduxfastsub->ai_cmd_running) {
                printk("comedi%d: ai_cmd not possible. Another ai_cmd is running.\n",
                       dev->minor);
@@ -871,6 +875,9 @@ static int usbduxfast_ai_cmd(comedi_device *dev, comedi_subdevice *s)
        // set current channel of the running aquisition to zero
        s->async->cur_chan = 0;
 
+       // ignore the first 5 buffers from the device
+       this_usbduxfastsub->ignore=PACKETS_TO_IGNORE;
+
        if (cmd->chanlist_len>0) {
                gain = CR_RANGE(cmd->chanlist[0]);
                for(i=0; i < cmd->chanlist_len; ++i ) {
@@ -1346,7 +1353,6 @@ static void tidy_up(usbduxfastsub_t* usbduxfastsub_tmp) {
                usbduxfastsub_tmp->dux_commands=NULL;
        }
        usbduxfastsub_tmp->ai_cmd_running=0;
-       usbduxfastsub_tmp->ai_insn_running=0;
 }