Messages in this thread | | | Date | Tue, 24 Jan 2023 09:39:16 +0100 | Subject | Re: [PATCH v6 0/6] staging: vc04_services: vchiq: Register devices with a custom bus_type | From | Stefan Wahren <> |
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Hi Umang,
Am 24.01.23 um 06:39 schrieb Umang Jain: > 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 ? From user perspective this behavior change is a regression. So we need automatic probing to convince user to use the mainline kernel. >>> >>> 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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