improved error handling a bit

diff --git a/comedi/drivers/comedi_rt_timer.c b/comedi/drivers/comedi_rt_timer.c
index 0300d3dce0dda2f5a963041bbd72ffc22c959477..dc60111bbf9ac4159999d6eb0c55ee11176ab103 100644 (file)
--- a/comedi/drivers/comedi_rt_timer.c
+++ b/comedi/drivers/comedi_rt_timer.c
@@ -29,7 +29,6 @@ Options:
        [1] - subdevice number you wish to emulate commands for
 
 TODO:
-       Improve error handling
        Support for digital io commands could be added, except I can't see why
                anyone would want to use them
        Fix it so more that one comedi_rt_timer can be configured at once
@@ -97,9 +96,6 @@ static inline RTIME nano2count(long long ns)
 #include <rtai_sched.h>
 #endif
 
-/* Change this if you need more channels */
-#define N_CHANLIST 16
-
 static int timer_attach(comedi_device *dev,comedi_devconfig *it);
 static int timer_detach(comedi_device *dev);
 static comedi_driver driver_timer={
@@ -119,12 +115,11 @@ typedef struct{
        comedi_subdevice *s;
        RT_TASK rt_task;
        int soft_irq;
-       int chanlist[N_CHANLIST];
 }timer_private;
 #define devpriv ((timer_private *)dev->private)
 
 
-static comedi_device *broken_rt_dev;
+static comedi_device *broken_rt_dev = NULL;
 
 #ifdef CONFIG_COMEDI_RTL
 static void timer_interrupt(int irq,void *d,struct pt_regs * regs)
@@ -196,8 +191,9 @@ static void timer_ai_task_func(int d)
                                CR_AREF(cmd->chanlist[i]),
                                &data);
                        if(ret<0){
-                               /* eek! */
-                               rt_printk("eek!\n");
+                               comedi_error(dev, "read error");
+                               comedi_error_done(dev, s);
+                               goto cleanup;
                        }
                        if(cmd->convert_src == TRIG_TIMER)
                                rt_task_wait_period();
@@ -208,11 +204,12 @@ static void timer_ai_task_func(int d)
                s->async->events = 0;
        }
        comedi_done(dev,s);
-       rt_pend_linux_srq(devpriv->soft_irq);
 
-       rt_task_delete(&devpriv->rt_task);
+cleanup:
 
-       /* eek! */
+       rt_pend_linux_srq(devpriv->soft_irq);
+       // we are deleting ourself here, no lines afterwards will be executed!
+       rt_task_delete(&devpriv->rt_task);
 }
 
 static void timer_ao_task_func(int d)
@@ -229,8 +226,9 @@ static void timer_ao_task_func(int d)
                for(i=0;i<cmd->scan_end_arg;i++){
                        data = buf_remove(dev,s);
                        if(data < 0) {
-                               /* eek! */
-                               rt_printk("eek!\n");
+                               comedi_error(dev, "buffer underrun");
+                               comedi_error_done(dev, s);
+                               goto cleanup;
                        }
                        ret = comedi_data_write(devpriv->device,devpriv->subd,
                                CR_CHAN(cmd->chanlist[i]),
@@ -238,8 +236,9 @@ static void timer_ao_task_func(int d)
                                CR_AREF(cmd->chanlist[i]),
                                data);
                        if(ret<0){
-                               /* eek! */
-                               rt_printk("eek!\n");
+                               comedi_error(dev, "write error");
+                               comedi_error_done(dev, s);
+                               goto cleanup;
                        }
                        if(cmd->convert_src == TRIG_TIMER)
                                rt_task_wait_period();
@@ -251,11 +250,12 @@ static void timer_ao_task_func(int d)
                        rt_task_wait_period();
        }
        comedi_done(dev,s);
-       rt_pend_linux_srq(devpriv->soft_irq);
 
-       rt_task_delete(&devpriv->rt_task);
+cleanup:
 
-       /* eek! */
+       rt_pend_linux_srq(devpriv->soft_irq);
+       // we are deleting ourself here, no lines afterwards will be executed!
+       rt_task_delete(&devpriv->rt_task);
 }
 
 static int timer_insn(comedi_device *dev,comedi_subdevice *s,
@@ -428,8 +428,7 @@ static int timer_cmd(comedi_device *dev,comedi_subdevice *s)
 static int timer_cancel(comedi_device *dev,comedi_subdevice *s)
 {
        rt_task_delete(&devpriv->rt_task);
-
-       comedi_unlock(devpriv->device,devpriv->subd);
+       rt_pend_linux_srq(devpriv->soft_irq);
 
        return 0;
 }
@@ -441,6 +440,13 @@ static int timer_attach(comedi_device *dev,comedi_devconfig *it)
 
        printk("comedi%d: timer: ",dev->minor);
 
+       if(broken_rt_dev)
+       {
+               printk("Only a single comedi_rt_timer can be configured at once.\n"
+                       " Hopefully this will be fixed in the future.\n");
+               return -EBUSY;
+       }
+
        dev->board_name="timer";
 
        dev->n_subdevices=2;
@@ -530,6 +536,8 @@ static int timer_detach(comedi_device *dev)
                }
        }
 
+       broken_rt_dev = NULL;
+
        return 0;
 }