[PATCH v2 01/11] spi: pxa2xx: Wrap pxa_ssp_request() to be device managed resource

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

In the error path or remove path the reference counter in PXA SSP driver
may be dropped before the other resources, that were allocated after
bumbing the reference counter. This breaks reversed order of freeing and
might have an undesired side effects. Prevent this from happening by
wrapping pxa_ssp_request() to be device managed resource.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 drivers/spi/spi-pxa2xx.c | 50 +++++++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 18 deletions(-)

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index efe76d0c21bb..820a3702447a 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1304,6 +1304,27 @@ pxa2xx_spi_init_ssp(struct platform_device *pdev, struct ssp_device *ssp, enum p
 	return 0;
 }
 
+static void pxa2xx_spi_ssp_release(void *ssp)
+{
+	pxa_ssp_free(ssp);
+}
+
+static struct ssp_device *pxa2xx_spi_ssp_request(struct platform_device *pdev)
+{
+	struct ssp_device *ssp;
+	int status;
+
+	ssp = pxa_ssp_request(pdev->id, pdev->name);
+	if (!ssp)
+		return ssp;
+
+	status = devm_add_action_or_reset(&pdev->dev, pxa2xx_spi_ssp_release, ssp);
+	if (status)
+		return ERR_PTR(status);
+
+	return ssp;
+}
+
 static struct pxa2xx_spi_controller *
 pxa2xx_spi_init_pdata(struct platform_device *pdev)
 {
@@ -1331,11 +1352,11 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev)
 
 		type = (enum pxa_ssp_type)value;
 	} else {
-		ssp = pxa_ssp_request(pdev->id, pdev->name);
-		if (ssp) {
+		ssp = pxa2xx_spi_ssp_request(pdev);
+		if (IS_ERR(ssp))
+			return ERR_CAST(ssp);
+		if (ssp)
 			type = ssp->type;
-			pxa_ssp_free(ssp);
-		}
 	}
 
 	/* Validate the SSP type correctness */
@@ -1420,7 +1441,9 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 	}
 	dev_dbg(dev, "DMA burst size set to %u\n", platform_info->dma_burst_size);
 
-	ssp = pxa_ssp_request(pdev->id, pdev->name);
+	ssp = pxa2xx_spi_ssp_request(pdev);
+	if (IS_ERR(ssp))
+		return PTR_ERR(ssp);
 	if (!ssp)
 		ssp = &platform_info->ssp;
 
@@ -1431,11 +1454,9 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 		controller = devm_spi_alloc_target(dev, sizeof(*drv_data));
 	else
 		controller = devm_spi_alloc_host(dev, sizeof(*drv_data));
+	if (!controller)
+		return dev_err_probe(dev, -ENOMEM, "cannot alloc spi_controller\n");
 
-	if (!controller) {
-		status = dev_err_probe(dev, -ENOMEM, "cannot alloc spi_controller\n");
-		goto out_error_controller_alloc;
-	}
 	drv_data = spi_controller_get_devdata(controller);
 	drv_data->controller = controller;
 	drv_data->controller_info = platform_info;
@@ -1486,10 +1507,8 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 
 	status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
 			drv_data);
-	if (status < 0) {
-		dev_err_probe(dev, status, "cannot get IRQ %d\n", ssp->irq);
-		goto out_error_controller_alloc;
-	}
+	if (status < 0)
+		return dev_err_probe(dev, status, "cannot get IRQ %d\n", ssp->irq);
 
 	/* Setup DMA if requested */
 	if (platform_info->enable_dma) {
@@ -1619,8 +1638,6 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 	pxa2xx_spi_dma_release(drv_data);
 	free_irq(ssp->irq, drv_data);
 
-out_error_controller_alloc:
-	pxa_ssp_free(ssp);
 	return status;
 }
 
@@ -1646,9 +1663,6 @@ static void pxa2xx_spi_remove(struct platform_device *pdev)
 
 	/* Release IRQ */
 	free_irq(ssp->irq, drv_data);
-
-	/* Release SSP */
-	pxa_ssp_free(ssp);
 }
 
 static int pxa2xx_spi_suspend(struct device *dev)
-- 
2.43.0.rc1.1336.g36b5255a03ac