Re: [PATCH] arm64: defconfig: Enable secure QFPROM driver

[Mukesh Ojha <quic_mojha@quicinc.com>]

On Wed, Jun 19, 2024 at 04:14:50PM +0300, Dmitry Baryshkov wrote:
> On Wed, Jun 19, 2024 at 05:40:42PM GMT, Mukesh Ojha wrote:
> > On Wed, Jun 19, 2024 at 01:08:48PM +0200, Krzysztof Kozlowski wrote:
> > > On 19/06/2024 12:56, Komal Bajaj wrote:
> > > > Enable the secure QFPROM driver which is used by QDU1000
> > > 
> > > Qualcomm QDU1000. You are changing kernel-wide defconfig, not some
> > > Qualcomm downstream stuff.
> > > 
> > > > platform for reading the secure qfprom region to get the
> > > > DDR channel configuration.
> > > > 
> > > > Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
> > > > ---
> > > >  arch/arm64/configs/defconfig | 1 +
> > > >  1 file changed, 1 insertion(+)
> > > > 
> > > > diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
> > > > index 838b4466d6f6..c940437ae1b3 100644
> > > > --- a/arch/arm64/configs/defconfig
> > > > +++ b/arch/arm64/configs/defconfig
> > > > @@ -1575,6 +1575,7 @@ CONFIG_NVMEM_LAYERSCAPE_SFP=m
> > > >  CONFIG_NVMEM_MESON_EFUSE=m
> > > >  CONFIG_NVMEM_MTK_EFUSE=y
> > > >  CONFIG_NVMEM_QCOM_QFPROM=y
> > > > +CONFIG_NVMEM_QCOM_SEC_QFPROM=y
> > > 
> > > Module
> > 
> > Should not this be inline with what CONFIG_NVMEM_QCOM_QFPROM is having ?
> > Either both CONFIG_NVMEM_QCOM_QFPROM and CONFIG_NVMEM_QCOM_SEC_QFPROM
> > should be m or both y
> 
> Looking back in time, CONFIG_NVMEM_QCOM_QFPROM was enabled as built-in
> to get TSENS to work (which makes sense, we don't want the CPUs to
> burn). What the actual users for NVMEM_QCOM_SEC_QFPROM?


CONFIG_NVMEM_QCOM_QFPROM and CONFIG_NVMEM_QCOM_SEC_QFPROM are similar driver
for same device and only difference is register region lies in secure space
for the latter;

Currently, LLCC is the only client for CONFIG_NVMEM_QCOM_SEC_QFPROM, however
if someday if the region lies in non-secure space in that case, client
started depending on CONFIG_NVMEM_QCOM_QFPROM.

It reminds me, we have not yet put depends on for LLCC on NVMEM_QCOM_SEC_QFPROM
doing which is resulting in recursive dependency[1].

It looks we need to select NVMEM_QCOM_SEC_QFPROM from QCOM_LLCC config and that
may not need config enablement here.

[1]
fs/sysfs/Kconfig:2:error: recursive dependency detected!
fs/sysfs/Kconfig:2:     symbol SYSFS is selected by CONFIGFS_FS
fs/configfs/Kconfig:2:  symbol CONFIGFS_FS is selected by GPIO_SIM
drivers/gpio/Kconfig:1884:      symbol GPIO_SIM depends on GPIOLIB
drivers/gpio/Kconfig:6: symbol GPIOLIB is selected by I2C_MUX_LTC4306
drivers/i2c/muxes/Kconfig:47:   symbol I2C_MUX_LTC4306 depends on I2C_MUX
drivers/i2c/Kconfig:62: symbol I2C_MUX is selected by DRM_SII902X
drivers/gpu/drm/bridge/Kconfig:270:     symbol DRM_SII902X depends on DRM_BRIDGE
drivers/gpu/drm/bridge/Kconfig:2:       symbol DRM_BRIDGE is selected by DRM_MSM
drivers/gpu/drm/msm/Kconfig:3:  symbol DRM_MSM depends on QCOM_LLCC
drivers/soc/qcom/Kconfig:47:    symbol QCOM_LLCC depends on NVMEM_QCOM_SEC_QFPROM
drivers/nvmem/Kconfig:230:      symbol NVMEM_QCOM_SEC_QFPROM depends on NVMEM
drivers/nvmem/Kconfig:2:        symbol NVMEM is selected by EEPROM_AT24
drivers/misc/eeprom/Kconfig:4:  symbol EEPROM_AT24 depends on SYSFS
For a resolution refer to Documentation/kbuild/kconfig-language.rst

-Mukesh

> 
> > 
> > -Mukesh
> > > 
> > > >  CONFIG_NVMEM_RMEM=m
> > > >  CONFIG_NVMEM_ROCKCHIP_EFUSE=y
> > > >  CONFIG_NVMEM_ROCKCHIP_OTP=y
> > > > --
> > > > 2.42.0
> > > > 
> > > 
> > > Best regards,
> > > Krzysztof
> > > 
> 
> -- 
> With best wishes
> Dmitry