spi: fix resource leaks on device setup failure

Make sure to call controller cleanup() on late device setup failures to avoid leaking resources allocated by setup().

---
 drivers/spi/spi.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

index 9fe9f99183bf..cb00619864cf 100644
@@ -4091,7 +4091,7 @@ int spi_setup(struct spi_device *spi)
 	status = spi_set_cs_timing(spi);
 	if (status) {
 		mutex_unlock(&spi->controller->io_mutex);
-		return status;
+		goto err_cleanup;
 	}
 
 	if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {

@@ -4100,7 +4100,7 @@ int spi_setup(struct spi_device *spi)
 			mutex_unlock(&spi->controller->io_mutex);
 			dev_err(&spi->controller->dev, "Failed to power device: %d\n",
 				status);
-			return status;
+			goto err_cleanup;
 		}
 
 		/*

@@ -4136,6 +4136,12 @@ int spi_setup(struct spi_device *spi)
 			status);
 
 	return status;
+
+err_cleanup:
+	if (spi->controller->cleanup)
+		spi->controller->cleanup(spi);
+
+	return status;
 }
 EXPORT_SYMBOL_GPL(spi_setup);
 

2.52.0

It's when spi_add_device() device fails in spi_setup() that cleanup() may no longer be called.

	spi_add_device()
	  __spi_add_device()
	    spi_setup()
	      controller->setup()
	      return -<errno>;

And there are drivers that allocate memory in the controller->setup() callback which is released in ->cleanup() (e.g. atmel_spi_setup() and atmel_spi_cleanup()).

From a quick look at some of the drivers it did not seem limited to memory allocations.

But I see now that not all of them can handle cleanup() being called more than once, which could indeed happen if a later call to spi_setup() fails after the device has been added.

We could set a flag to track whether setup() has ever been called successfully, or make sure that cleanup() can be called more than once for all drivers.

I open-coded as I'm matching the call to ->setup() inside spi_setup() with ->cleanup() (i.e. not spi_setup() with spi_cleanup()).

Johan