[PATCH] spufs: fix context-switch decrementer code
authorJordi Caubet <jordi_caubet@es.ibm.com>
Wed, 12 Apr 2006 15:44:27 +0000 (17:44 +0200)
committerPaul Mackerras <paulus@samba.org>
Thu, 13 Apr 2006 16:38:46 +0000 (09:38 -0700)
We found that when the 'decrementer' is saved, the PPE saves the current
time 'csa->suspend_time'. When restoring the 'decrementer', (Step 34)
decrementer seems to be adjusted with the number of cycles th= at a spu
thread has not been running.

In that code it is missing a substract ('-') because 'delta_time' is
assigned a not substracted(see bellow).

Acked-by: Mark Nutter <mnutter@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/platforms/cell/spufs/switch.c

index 97898d5d34e5c0539d942d4a7373c73eb6c3ff04..1726bfe38ee08f5dcd1aa3a198f43c7e086a2129 100644 (file)
@@ -1297,7 +1297,7 @@ static inline void setup_decr(struct spu_state *csa, struct spu *spu)
                cycles_t resume_time = get_cycles();
                cycles_t delta_time = resume_time - csa->suspend_time;
 
-               csa->lscsa->decr.slot[0] = delta_time;
+               csa->lscsa->decr.slot[0] -= delta_time;
        }
 }