device: incompatible change in return value of I/O methods.

(input|output)_cset change returned value:
* 0 if the acquisition is already done
* -EAGAIN if the acquisition will be completed in the future (must use
  data_done)
* Other error code if needed

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>

drivers/zio-zero.c

@@ -43,13 +43,13 @@ static int zzero_input(struct zio_cset *cset)
 				data[i] = datum++;
 		}
 	}
-	return 1; /* Already done */
+	return 0; /* Already done */
 }
 
 static int zzero_output(struct zio_cset *cset)
 {
 	/* We just eat data, like /dev/zero and /dev/null */
-	return 1; /* Already done */
+	return 0; /* Already done */
 }
 
 static const struct zio_device_operations zzero_d_op = {

zio-sys.c

@@ -200,7 +200,7 @@ static void __zio_fire_input_trigger(struct zio_ti *ti)
 		}
 		chan->active_block = block;
 	}
-	if (zdev->d_op->input_cset(cset)) {
+	if (!zdev->d_op->input_cset(cset)) {
 		/* It succeeded immediately */
 		ti->t_op->data_done(cset);
 	}
@@ -214,7 +214,7 @@ static void __zio_fire_output_trigger(struct zio_ti *ti)
 	pr_debug("%s:%d\n", __func__, __LINE__);
 
 	/* We are expected to already have a block in active channels */
-	if (zdev->d_op->output_cset(cset)) {
+	if (!zdev->d_op->output_cset(cset)) {
 		/* It succeeded immediately */
 		ti->t_op->data_done(cset);
 	}