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Diffstat (limited to 'arch/powerpc/platforms/cell/spufs/file.c')
-rw-r--r--arch/powerpc/platforms/cell/spufs/file.c46
1 files changed, 27 insertions, 19 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index adb5abb9af5..f139cd8b594 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -2503,30 +2503,38 @@ static ssize_t spufs_switch_log_read(struct file *file, char __user *buf,
char tbuf[128];
int width;
- if (file->f_flags & O_NONBLOCK) {
- if (spufs_switch_log_used(ctx) == 0) {
+ if (spufs_switch_log_used(ctx) == 0) {
+ if (cnt > 0) {
+ /* If there's data ready to go, we can
+ * just return straight away */
+ break;
+
+ } else if (file->f_flags & O_NONBLOCK) {
error = -EAGAIN;
break;
+
+ } else {
+ /* spufs_wait will drop the mutex and
+ * re-acquire, but since we're in read(), the
+ * file cannot be _released (and so
+ * ctx->switch_log is stable).
+ */
+ error = spufs_wait(ctx->switch_log->wait,
+ spufs_switch_log_used(ctx) > 0);
+
+ /* On error, spufs_wait returns without the
+ * state mutex held */
+ if (error)
+ return error;
+
+ /* We may have had entries read from underneath
+ * us while we dropped the mutex in spufs_wait,
+ * so re-check */
+ if (spufs_switch_log_used(ctx) == 0)
+ continue;
}
- } else {
- /* spufs_wait will drop the mutex and re-acquire,
- * but since we're in read(), the file cannot be
- * _released (and so ctx->switch_log is stable).
- */
- error = spufs_wait(ctx->switch_log->wait,
- spufs_switch_log_used(ctx) > 0);
-
- /* On error, spufs_wait returns without the
- * state mutex held */
- if (error)
- return error;
}
- /* We may have had entries read from underneath us while we
- * dropped the mutex in spufs_wait, so re-check */
- if (ctx->switch_log->head == ctx->switch_log->tail)
- continue;
-
width = switch_log_sprint(ctx, tbuf, sizeof(tbuf));
if (width < len)
ctx->switch_log->tail =