Re: [PATCH v2 -next] drm/vc4: Fix build error when CONFIG_DRM_VC4=y && CONFIG_RASPBERRYPI_FIRMWARE=m

[Zhengbin (OSKernel)]

On 2022/3/25 21:05, Maxime Ripard wrote:
> Hi,
>
> On Fri, Mar 25, 2022 at 10:18:31AM +0800, Zheng Bin wrote:
> > If CONFIG_DRM_VC4=y, CONFIG_RASPBERRYPI_FIRMWARE=m, CONFIG_COMPILE_TEST=n,
> > bulding fails:
> >
> > drivers/gpu/drm/vc4/vc4_drv.o: In function `vc4_drm_bind':
> > vc4_drv.c:(.text+0x320): undefined reference to `rpi_firmware_get'
> > vc4_drv.c:(.text+0x320): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `rpi_firmware_get'
> > vc4_drv.c:(.text+0x34c): undefined reference to `rpi_firmware_property'
> > vc4_drv.c:(.text+0x34c): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `rpi_firmware_property'
> > vc4_drv.c:(.text+0x354): undefined reference to `rpi_firmware_put'
> > vc4_drv.c:(.text+0x354): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `rpi_firmware_put'
> >
> > Make DRM_VC4 depends on RASPBERRYPI_FIRMWARE || COMPILE_TEST to fix this.
> >
> > Fixes: c406ad5e4a85 ("drm/vc4: Notify the firmware when DRM is in charge")
> > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > Signed-off-by: Zheng Bin <zhengbin13@xxxxxxxxxx>
> > ---
> > v2: follow Maxime's advise, add RASPBERRYPI_FIRMWARE as an additional depends
> >   drivers/gpu/drm/vc4/Kconfig | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/vc4/Kconfig b/drivers/gpu/drm/vc4/Kconfig
> > index de3424fed2fc..92d74ba7c449 100644
> > --- a/drivers/gpu/drm/vc4/Kconfig
> > +++ b/drivers/gpu/drm/vc4/Kconfig
> > @@ -2,6 +2,7 @@
> >   config DRM_VC4
> >   	tristate "Broadcom VC4 Graphics"
> >   	depends on ARCH_BCM || ARCH_BCM2835 || COMPILE_TEST
> > +	depends on RASPBERRYPI_FIRMWARE || COMPILE_TEST
> Why do we need the || COMPILE_TEST here?
>
> The rpi_firmware_get, _property and _put functions aren't define if
> RASPBERRYPI_FIRMWARE, so we need that dependency every time, even if
> COMPILE_TEST is set?

include/soc/bcm2835/raspberrypi-firmware.h

#if IS_ENABLED(CONFIG_RASPBERRYPI_FIRMWARE)

struct rpi_firmware *rpi_firmware_get(struct device_node 
*firmware_node);/_property/_put

#else    -->empty function

 static inline struct rpi_firmware *rpi_firmware_get(struct device_node 
*firmware_node)/_property/_put
{
         return NULL;
 }
#endif


We can refer to drivers/pwm/Kconfig

config PWM_RASPBERRYPI_POE
         tristate "Raspberry Pi Firwmware PoE Hat PWM support"
         # Make sure not 'y' when RASPBERRYPI_FIRMWARE is 'm'. This can 
only
        # happen when COMPILE_TEST=y, hence the added 
!RASPBERRYPI_FIRMWARE.
         depends on RASPBERRYPI_FIRMWARE || (COMPILE_TEST && 
!RASPBERRYPI_FIRMWARE)  -->There is no need to add (&& 
!RASPBERRYPI_FIRMWARE)

> Maxime