powerpc/spufs: fix missed stop-and-signal event

There is a delay in the transition to the stopped state for class 2
interrupts. In some cases, the controlling thread detects the state of
the spu as running, and goes back to sleep resulting in a hung
application as the event is missed.

This change detects the stop condition and re-generates the wakeup event
after a context save.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index cd72567..e929e70 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -407,6 +407,8 @@ static int has_affinity(struct spu_context *ctx)
  */
 static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
 {
+       u32 status;
+
        spu_context_trace(spu_unbind_context__enter, ctx, spu);
 
        spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
@@ -452,6 +454,9 @@ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
        /* This maps the underlying spu state to idle */
        spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
        ctx->spu = NULL;
+
+       if (spu_stopped(ctx, &status))
+               wake_up_all(&ctx->stop_wq);
 }
 
 /**