powerpc/spufs: wait for stable spu status in spu_stopped()

If the spu is stopping (ie, the SPU_STATUS_RUNNING bit is still set),
re-read the register to get the final stopped value.

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

1 files changed, 13 insertions, 5 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index b7493b865812..0046bcfe495a 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -51,14 +51,22 @@ int spu_stopped(struct spu_context *ctx, u32 *stat)
         u64 dsisr;
         u32 stopped;
 
-        *stat = ctx->ops->status_read(ctx);
+        stopped = SPU_STATUS_INVALID_INSTR | SPU_STATUS_SINGLE_STEP |
+                SPU_STATUS_STOPPED_BY_HALT | SPU_STATUS_STOPPED_BY_STOP;
 
-        if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
+top:
+        *stat = ctx->ops->status_read(ctx);
+        if (*stat & stopped) {
+                /*
+                 * If the spu hasn't finished stopping, we need to
+                 * re-read the register to get the stopped value.
+                 */
+                if (*stat & SPU_STATUS_RUNNING)
+                        goto top;
                 return 1;
+        }
 
-        stopped = SPU_STATUS_INVALID_INSTR | SPU_STATUS_SINGLE_STEP |
-                SPU_STATUS_STOPPED_BY_HALT | SPU_STATUS_STOPPED_BY_STOP;
-        if (!(*stat & SPU_STATUS_RUNNING) && (*stat & stopped))
+        if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
                 return 1;
 
         dsisr = ctx->csa.class_0_dsisr;