[PATCH v12 2/6] staging: vc04_services: bcm2835-audio: Explicitly set DMA mask

From: Umang Jain
Date: Sat Sep 23 2023 - 10:32:20 EST


In the following patches, vchiq_arm will be migrated to create and use
its own bus and all the vchiq drivers (bcm2835-camera, bcm2835-audio)
will be registered to it. Since the platform driver/device model
internally sets the DMA mask for its registered devices, we would have
to do it ourself when we remove the platform driver/device registration
for vchiq devices.

This patch explicitly sets the DMA mask to bcm2835-audio so as not
to introduce a regression when we move away from platform
device/driver model.

Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>
---
drivers/staging/vc04_services/bcm2835-audio/bcm2835.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
index 00bc898b0189..f3ad2543d1c0 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
@@ -3,6 +3,7 @@

#include <linux/platform_device.h>

+#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
@@ -273,6 +274,12 @@ static int snd_bcm2835_alsa_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
int err;

+ err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ if (err) {
+ dev_err(dev, "dma_set_mask_and_coherent failed: %d\n", err);
+ return err;
+ }
+
if (num_channels <= 0 || num_channels > MAX_SUBSTREAMS) {
num_channels = MAX_SUBSTREAMS;
dev_warn(dev, "Illegal num_channels value, will use %u\n",
--
2.40.1