#1120854 linux-image-arm64: Enable dma engine for Renesas RZ platform

Package:
src:linux
Source:
src:linux
Submitter:
John Vincent
Date:
2026-07-08 19:25:05 UTC
Severity:
normal
Tags:
#1120854#5
Date:
2025-11-17 15:15:44 UTC
From:
To:
Dear Maintainer,

For RZ platform the DMA engine needs enabling using the kernel config:

CONFIG_RZ_DMAC=m

Please support to enable this config in debian kernel config:

https://salsa.debian.org/kernel-team/linux/-/blob/debian/latest/debian/config/arm64/config

#1120854#14
Date:
2025-11-17 15:23:50 UTC
From:
To:
Dear Maintainer

I've attached the patch for enabling CONFIG_RZ_DMAC=m

Bug ticket for this patch: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1120854

Best Regards
John

#1120854#19
Date:
2025-11-17 19:39:04 UTC
From:
To:
Control: tag -1 - d-i upstream
Control: tag -1 moreinfo
[...]

This is the second bug you've opened requesting a single driver for the
RZ platform.  Can you provide a list of *all* the drivers that should be
enabled?  From a quick look through the Kconfig files it seems like we
are also missing RTC, watchdog, PWM, reset, DRM, and other drivers.

Ben.

#1120854#28
Date:
2025-11-18 19:40:13 UTC
From:
To:
Hi Ben

I've updated the patch file to include additional configs.

- DMA: RZ DMAC (CONFIG_RZ_DMAC)
- Display: DRM R-Car DU, VSP, HDMI, MIPI DSI, CMM, LVD
- Media: FCP, FDP1, VSP1, CRU, CSI2, VIN, ISP, DRIF
- I2C: R-Car I2C controller
- MMC: SDHI with SYS_DMAC and INTERNAL_DMAC
- PHY: USB3 support for R-Car Gen3
- PWM: R-Car PWM controller
- Watchdog: Renesas WDT
- Clock source: Renesas OSTM
- Ethernet : Gen4 PTP
- ADC: RZ ADC
- Thermal: RZ Thermal

Best Regards
John

Control: tag -1 - d-i upstream
Control: tag -1 moreinfo
[...]

This is the second bug you've opened requesting a single driver for the RZ platform.  Can you provide a list of *all* the drivers that should be enabled?  From a quick look through the Kconfig files it seems like we are also missing RTC, watchdog, PWM, reset, DRM, and other drivers.

Ben.

#1120854#35
Date:
2025-11-19 12:05:55 UTC
From:
To:
Hi Ben

I've made one change (below) and updated the patch
CONFIG_RZ_DMAC=y ( from CONFIG_RZ_DMAC=m)
The reason being the DMA engine is core device, this needs to be enabled
for the serial device to be working and hence it needs to be built in.

I've updated the config enabled based on the groups for the reference:

##
## file: drivers/clocksource/Kconfig
##
CONFIG_RENESAS_OSTM=y

##
## file: drivers/dma/sh/Kconfig
##
CONFIG_RZ_DMAC=y

##
## file: drivers/gpu/drm/renesas/rcar-du/Kconfig
##
CONFIG_DRM_RCAR_DU=m
CONFIG_DRM_RCAR_VSP=m
CONFIG_DRM_RCAR_CMM=m
CONFIG_DRM_RCAR_DW_HDMI=m
CONFIG_DRM_RCAR_LVD=m
CONFIG_DRM_RCAR_MIPI_DSI=m

##
## file: drivers/i2c/busses/Kconfig
##
CONFIG_I2C_RCAR=m

##
## file: drivers/iio/adc/Kconfig
##
CONFIG_RZG2L_ADC=m

##
## file: drivers/media/platform/renesas/Kconfig
##
CONFIG_VIDEO_RENESAS_FCP=m
CONFIG_VIDEO_RENESAS_FDP1=m
CONFIG_VIDEO_RENESAS_VSP1=m
CONFIG_VIDEO_RCAR_ISP=m
CONFIG_VIDEO_RCAR_DRIF=m

##
## drivers/media/platform/renesas/rzg2l-cru/Kconfig
##
CONFIG_VIDEO_RZG2L_CRU=m
CONFIG_VIDEO_RZG2L_CSI2=m

##
## file: drivers/media/platform/renesas/rcar-vin/Kconfig
##
CONFIG_VIDEO_RCAR_CSI2=m
CONFIG_VIDEO_RCAR_VIN=m

##
## file: drivers/mmc/host/Kconfig
##
CONFIG_MMC_SDHI_SYS_DMAC=m
CONFIG_MMC_SDHI_INTERNAL_DMAC=m

##
## file: drivers/net/ethernet/renesas/Kconfig
##
CONFIG_RENESAS_GEN4_PTP=m

##
## file: drivers/phy/renesas/Kconfig
##
CONFIG_PHY_RCAR_GEN3_USB3=m

##
## file: drivers/pwm/Kconfig
##
CONFIG_PWM_RCAR=m

##
## file: drivers/thermal/Kconfig
##
CONFIG_RZG2L_THERMAL=m

##
## file: drivers/watchdog/Kconfig
##
CONFIG_RENESAS_RZG2LWDT=m

Best Regards
John

Hi Ben

I've updated the patch file to include additional configs.

- DMA: RZ DMAC (CONFIG_RZ_DMAC)
- Display: DRM R-Car DU, VSP, HDMI, MIPI DSI, CMM, LVD
- Media: FCP, FDP1, VSP1, CRU, CSI2, VIN, ISP, DRIF
- I2C: R-Car I2C controller
- MMC: SDHI with SYS_DMAC and INTERNAL_DMAC
- PHY: USB3 support for R-Car Gen3
- PWM: R-Car PWM controller
- Watchdog: Renesas WDT
- Clock source: Renesas OSTM
- Ethernet : Gen4 PTP
- ADC: RZ ADC
- Thermal: RZ Thermal

Best Regards
John
Control: tag -1 - d-i upstream
Control: tag -1 moreinfo
[...]

This is the second bug you've opened requesting a single driver for the RZ platform.  Can you provide a list of *all* the drivers that should be enabled?  From a quick look through the Kconfig files it seems like we are also missing RTC, watchdog, PWM, reset, DRM, and other drivers.

Ben.

#1120854#40
Date:
2025-11-19 13:29:57 UTC
From:
To:
I've created MR https://salsa.debian.org/kernel-team/linux/-/merge_requests/1720 for this change.

Hi Ben

I've made one change (below) and updated the patch CONFIG_RZ_DMAC=y ( from CONFIG_RZ_DMAC=m) The reason being the DMA engine is core device, this needs to be enabled for the serial device to be working and hence it needs to be built in.

I've updated the config enabled based on the groups for the reference:

##
## file: drivers/clocksource/Kconfig
##
CONFIG_RENESAS_OSTM=y

##
## file: drivers/dma/sh/Kconfig
##
CONFIG_RZ_DMAC=y

##
## file: drivers/gpu/drm/renesas/rcar-du/Kconfig
##
CONFIG_DRM_RCAR_DU=m
CONFIG_DRM_RCAR_VSP=m
CONFIG_DRM_RCAR_CMM=m
CONFIG_DRM_RCAR_DW_HDMI=m
CONFIG_DRM_RCAR_LVD=m
CONFIG_DRM_RCAR_MIPI_DSI=m

##
## file: drivers/i2c/busses/Kconfig
##
CONFIG_I2C_RCAR=m

##
## file: drivers/iio/adc/Kconfig
##
CONFIG_RZG2L_ADC=m

##
## file: drivers/media/platform/renesas/Kconfig
##
CONFIG_VIDEO_RENESAS_FCP=m
CONFIG_VIDEO_RENESAS_FDP1=m
CONFIG_VIDEO_RENESAS_VSP1=m
CONFIG_VIDEO_RCAR_ISP=m
CONFIG_VIDEO_RCAR_DRIF=m

##
## drivers/media/platform/renesas/rzg2l-cru/Kconfig
##
CONFIG_VIDEO_RZG2L_CRU=m
CONFIG_VIDEO_RZG2L_CSI2=m

##
## file: drivers/media/platform/renesas/rcar-vin/Kconfig
##
CONFIG_VIDEO_RCAR_CSI2=m
CONFIG_VIDEO_RCAR_VIN=m

##
## file: drivers/mmc/host/Kconfig
##
CONFIG_MMC_SDHI_SYS_DMAC=m
CONFIG_MMC_SDHI_INTERNAL_DMAC=m

##
## file: drivers/net/ethernet/renesas/Kconfig
##
CONFIG_RENESAS_GEN4_PTP=m

##
## file: drivers/phy/renesas/Kconfig
##
CONFIG_PHY_RCAR_GEN3_USB3=m

##
## file: drivers/pwm/Kconfig
##
CONFIG_PWM_RCAR=m

##
## file: drivers/thermal/Kconfig
##
CONFIG_RZG2L_THERMAL=m

##
## file: drivers/watchdog/Kconfig
##
CONFIG_RENESAS_RZG2LWDT=m

Best Regards
John
Hi Ben

I've updated the patch file to include additional configs.

- DMA: RZ DMAC (CONFIG_RZ_DMAC)
- Display: DRM R-Car DU, VSP, HDMI, MIPI DSI, CMM, LVD
- Media: FCP, FDP1, VSP1, CRU, CSI2, VIN, ISP, DRIF
- I2C: R-Car I2C controller
- MMC: SDHI with SYS_DMAC and INTERNAL_DMAC
- PHY: USB3 support for R-Car Gen3
- PWM: R-Car PWM controller
- Watchdog: Renesas WDT
- Clock source: Renesas OSTM
- Ethernet : Gen4 PTP
- ADC: RZ ADC
- Thermal: RZ Thermal

Best Regards
John
Control: tag -1 - d-i upstream
Control: tag -1 moreinfo
[...]

This is the second bug you've opened requesting a single driver for the RZ platform.  Can you provide a list of *all* the drivers that should be enabled?  From a quick look through the Kconfig files it seems like we are also missing RTC, watchdog, PWM, reset, DRM, and other drivers.

Ben.