Correction of false i82527 IRQ stuck problem reported by Terence Soh.

The interrupt pending flag has to be clean even, if we cannot process
synchronous activities. The flags ensures, that they are processed
later in such case. The change requires testing, I have not get
to testing yet.

diff --git a/lincan/src/i82527.c b/lincan/src/i82527.c
index eb89220320d9d6832dc4e0aceaf3f65d57c5a8a3..58aa048ae79f938792b2dfeb2d9d77ff3ea858c8 100644 (file)
--- a/lincan/src/i82527.c
+++ b/lincan/src/i82527.c
@@ -601,8 +601,10 @@ void i82527_irq_update_filter(struct canchip_t *chip, struct msgobj_t *obj)
 }
 
 
 }
 
 

-void i82527_irq_sync_activities(struct canchip_t *chip, struct msgobj_t *obj)
+int i82527_irq_sync_activities(struct canchip_t *chip, struct msgobj_t *obj)

 {
 {

+       int job_done=0;
+

        while(!can_msgobj_test_and_set_fl(obj,TX_LOCK)) {
 
                if(can_msgobj_test_and_clear_fl(obj,TX_REQUEST)) {
        while(!can_msgobj_test_and_set_fl(obj,TX_LOCK)) {
 
                if(can_msgobj_test_and_clear_fl(obj,TX_REQUEST)) {


@@ -616,6 +618,8 @@ void i82527_irq_sync_activities(struct canchip_t *chip, struct msgobj_t *obj)
                        }
                }
 
                        }
                }
 

+               job_done=1;
+

                mb();
 
                can_msgobj_clear_fl(obj,TX_LOCK);
                mb();
 
                can_msgobj_clear_fl(obj,TX_LOCK);


@@ -625,6 +629,8 @@ void i82527_irq_sync_activities(struct canchip_t *chip, struct msgobj_t *obj)
                        continue;
                break;
        }
                        continue;
                break;
        }

+
+       return job_done;

 }
 
 int i82527_irq_handler(int irq, struct canchip_t *chip)
 }
 
 int i82527_irq_handler(int irq, struct canchip_t *chip)


@@ -679,7 +685,17 @@ int i82527_irq_handler(int irq, struct canchip_t *chip)
                        can_msgobj_set_fl(obj,TX_REQUEST);
                        
                        /* calls i82527_irq_write_handler synchronized with other invocations */
                        can_msgobj_set_fl(obj,TX_REQUEST);
                        
                        /* calls i82527_irq_write_handler synchronized with other invocations */

-                       i82527_irq_sync_activities(chip, obj);
+                       if(i82527_irq_sync_activities(chip, obj)<=0){
+                               /* The interrupt has to be cleared anyway */
+                               canobj_write_reg(chip,obj,(MVAL_UNC|TXIE_UNC|RXIE_UNC|INTPD_RES),iMSGCTL0);
+
+                               /* 
+                                * Rerun for case, that parallel activity on SMP or fully-preemptive
+                                * kernel result in preparation and finished sending of message
+                                * between above if and canobj_write_reg.
+                                */
+                               i82527_irq_sync_activities(chip, obj);
+                       }

                }
                else { 
 
                }
                else {