Messages in this thread | | | Date | Tue, 24 Jan 2023 11:09:31 +0530 | Subject | Re: [PATCH v6 0/6] staging: vc04_services: vchiq: Register devices with a custom bus_type | From | Umang Jain <> |
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Hi Stefan
On 1/23/23 10:58 PM, Stefan Wahren wrote: > Hi Umang, > > Am 23.01.23 um 08:48 schrieb Umang Jain: >> 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); > Yes, this patch fixes the errors above. But i noticed that the series > also break autoprobing of bcm2835-audio and bcm2835-camera.
For the diff concerned, I am still looking into why is this needed.
Regarding the autoprobing, I have noticed that as well. It seems the probing is automatic for platform driver/devices and we are moving away from the platform driver/devices. So, this is expected I suppose?
Reading from Documentation/driver-api/driver-model/platform.rst
""" Driver binding is performed automatically by the driver core, invoking driver probe() after finding a match between device and driver. If the probe() succeeds, the driver and device are bound as usual """
Should we retain this behavior ? >> >> 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/ >> >> Laurent, any thoughts on this please? >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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