[PATCH RFC 44/51] DMA-API: dcdbas: update DMA mask handing

Russell King
2013-08-01T22:18:42Z

dcdbas was explicitly initializing DMA masks thusly:
dcdbas_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
which bypasses the architecture check. Moreover, it is creating the
dcdbas_pdev device itself, and using the platform_device_register_full()
avoids some of this explicit initialization.

Convert the driver to use platform_device_register_full(), and as it
makes use of coherent DMA, also call dma_set_coherent_mask() to ensure
that the architecture gets to check the mask.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
drivers/firmware/dcdbas.c | 23 ++++++++++++-----------
1 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 8e77c02..61969cd 100644
--- a/drivers/firmware/dcdbas.c
+++ b/drivers/firmware/dcdbas.c
@@ -548,8 +548,9 @@ static int dcdbas_probe(struct platform_device *dev)
* BIOS SMI calls require buffer addresses be in 32-bit address space.
* This is done by setting the DMA mask below.
*/
- dcdbas_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
- dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
+ error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32));
+ if (error)
+ return error;

error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
if (error)
@@ -596,6 +597,12 @@ static struct platform_driver dcdbas_driver = {
.remove = dcdbas_remove,
};

+static const struct platform_device_info dcdbas_dev_info __initdata = {
+ .name = DRIVER_NAME,
+ .id = -1,
+ .dma_mask = DMA_BIT_MASK(32),
+};
+
/**
* dcdbas_init: initialize driver
*/
@@ -607,20 +614,14 @@ static int __init dcdbas_init(void)
if (error)
return error;

- dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
- if (!dcdbas_pdev) {
- error = -ENOMEM;
+ dcdbas_pdev = platform_device_register_full(&dcdbas_dev_info);
+ if (IS_ERR(dcdbas_pdev)) {
+ error = PTR_ERR(dcdbas_pdev);
goto err_unregister_driver;
}

- error = platform_device_add(dcdbas_pdev);
- if (error)
- goto err_free_device;
-
return 0;

- err_free_device:
- platform_device_put(dcdbas_pdev);
err_unregister_driver:
platform_driver_unregister(&dcdbas_driver);
return error;
--
1.7.4.4