Hi Phil,
Thank you for the response
On 1/25/23 1:17 AM, Phil Elwell wrote:
On 24/01/2023 8:41, Stefan Wahren wrote:
Hi Phil,
Am 23.01.23 um 09:58 schrieb Laurent Pinchart:
On Mon, Jan 23, 2023 at 01:18:30PM +0530, Umang Jain wrote:
Hi Stefan,
Thank for the testing.
On 1/23/23 5:04 AM, Stefan Wahren wrote:
Hi Umang,
Am 20.01.23 um 21:10 schrieb Umang Jain:
This series just introduces five extra patches for dropping include
directives from Makefiles (suggested by Greg KH) and rebased.
The main patch (6/6) removes platform device/driver abuse and moves
things to standard device/driver model using a custom_bus. Specific
details are elaborated in the commit message.
The patch series is based on top of d514392f17fd (tag:
next-20230120)
of linux-next.
applied this series on top of linux-next and build it with
arm/multi_v7_defconfig plus the following:
CONFIG_BCM_VIDEOCORE=y
CONFIG_BCM2835_VCHIQ=m
CONFIG_VCHIQ_CDEV=y
CONFIG_SND_BCM2835=m
CONFIG_VIDEO_BCM2835=m
CONFIG_BCM2835_VCHIQ_MMAL=m
and the devices doesn't register on Raspberry Pi 3 B Plus:
[ 25.523337] vchiq: module is from the staging directory, the
quality is unknown, you have been warned.
[ 25.541647] bcm2835_vchiq 3f00b840.mailbox: Failed to register
bcm2835_audio vchiq device
[ 25.553692] bcm2835_vchiq 3f00b840.mailbox: Failed to register
bcm2835-camera vchiq device
I was able to reproduce and it seems the issue here is the change
mentioned in the cover
- drop dma_set_mask_and_coherent
in V6.
(I usually test patches on RPi 4B with vcsm-cma and bcm2835-isp
applied
so my branch has the DMA hunk included while I was testing V6)
Below is the hunk which should resolve the issue.
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.c
@@ -6,6 +6,7 @@
*/
#include <linux/device/bus.h>
+#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/string.h>
@@ -72,6 +73,12 @@ int vchiq_device_register(struct device *parent,
const char *name)
device->dev.type = &vchiq_device_type;
device->dev.release = vchiq_device_release;
+ ret = dma_set_mask_and_coherent(&device->dev,
DMA_BIT_MASK(32));
+ if (ret < 0) {
+ vchiq_device_release(&device->dev);
+ return ret;
+ }
+
ret = device_register(&device->dev);
if (ret) {
put_device(&device->dev);
It seems we need to include the dma_set_mask_and_coherent() even if
bcm2835-audio, bcm2835-camera device doesn't do DMA? I need to look
into
why is that/
Do you have an answer for this?
That's because vchiq does use DMA for bulk transfers, it's just that
the DMA hardware
is driven from the VPU side. And even though the VPU can only address
1GB, it uses the
upper address bits to determine cacheability of accesses, hence the
need for 32-bit
DMA addresses.
Is it worth recording this as a comment in the patch?
Phil
