• Mauro Carvalho Chehab's avatar
    [media] Fix build when drivers are builtin and frontend modules · bb69ee27
    Mauro Carvalho Chehab authored
    There are a large number of reports that the media build is
    not compiling when some drivers are compiled as builtin, while
    the needed frontends are compiled as module.
    
    On the last one of such reports:
    	From: kbuild test robot <fengguang.wu@intel.com>
    	Subject: saa7134-dvb.c:undefined reference to `zl10039_attach'
    
    The .config file has:
    
    	CONFIG_VIDEO_SAA7134=y
    	CONFIG_VIDEO_SAA7134_DVB=y
    	# CONFIG_MEDIA_ATTACH is not set
    	CONFIG_DVB_ZL10039=m
    
    And it produces all those errors:
    
       drivers/built-in.o: In function `set_type':
       tuner-core.c:(.text+0x2f263e): undefined reference to `tea5767_attach'
       tuner-core.c:(.text+0x2f273e): undefined reference to `tda9887_attach'
       drivers/built-in.o: In function `tuner_probe':
       tuner-core.c:(.text+0x2f2d20): undefined reference to `tea5767_autodetection'
       drivers/built-in.o: In function `av7110_attach':
       av7110.c:(.text+0x330bda): undefined reference to `ves1x93_attach'
       av7110.c:(.text+0x330bf7): undefined reference to `stv0299_attach'
       av7110.c:(.text+0x330c63): undefined reference to `tda8083_attach'
       av7110.c:(.text+0x330d09): undefined reference to `ves1x93_attach'
       av7110.c:(.text+0x330d33): undefined reference to `tda8083_attach'
       av7110.c:(.text+0x330d5d): undefined reference to `stv0297_attach'
       av7110.c:(.text+0x330dbe): undefined reference to `stv0299_attach'
       drivers/built-in.o: In function `tuner_attach_dtt7520x':
       ngene-cards.c:(.text+0x3381cb): undefined reference to `dvb_pll_attach'
       drivers/built-in.o: In function `demod_attach_lg330x':
       ngene-cards.c:(.text+0x33828a): undefined reference to `lgdt330x_attach'
       drivers/built-in.o: In function `demod_attach_stv0900':
       ngene-cards.c:(.text+0x3383d5): undefined reference to `stv090x_attach'
       drivers/built-in.o: In function `cineS2_probe':
       ngene-cards.c:(.text+0x338b7f): undefined reference to `drxk_attach'
       drivers/built-in.o: In function `configure_tda827x_fe':
       saa7134-dvb.c:(.text+0x346ae7): undefined reference to `tda10046_attach'
       drivers/built-in.o: In function `dvb_init':
       saa7134-dvb.c:(.text+0x347283): undefined reference to `mt352_attach'
       saa7134-dvb.c:(.text+0x3472cd): undefined reference to `mt352_attach'
       saa7134-dvb.c:(.text+0x34731c): undefined reference to `tda10046_attach'
       saa7134-dvb.c:(.text+0x34733c): undefined reference to `tda10046_attach'
       saa7134-dvb.c:(.text+0x34735c): undefined reference to `tda10046_attach'
       saa7134-dvb.c:(.text+0x347378): undefined reference to `tda10046_attach'
       saa7134-dvb.c:(.text+0x3473db): undefined reference to `tda10046_attach'
       drivers/built-in.o:saa7134-dvb.c:(.text+0x347502): more undefined references to `tda10046_attach' follow
       drivers/built-in.o: In function `dvb_init':
       saa7134-dvb.c:(.text+0x347812): undefined reference to `mt352_attach'
       saa7134-dvb.c:(.text+0x347951): undefined reference to `mt312_attach'
       saa7134-dvb.c:(.text+0x3479a9): undefined reference to `mt312_attach'
    >> saa7134-dvb.c:(.text+0x3479c1): undefined reference to `zl10039_attach'
    
    This is happening because a builtin module can't use directly a symbol
    found on a module. By enabling CONFIG_MEDIA_ATTACH, the configuration
    becomes valid, as dvb_attach() macro loads the module if needed, making
    the symbol available to the builtin module.
    
    While this bug started to appear after the patches that use IS_DEFINED
    macro (like changeset 7b34be71), this
    bug is a way ancient than that.
    
    The thing is that, before the IS_DEFINED() patches, the logic used to be:
    
           && defined(MODULE))
    struct dvb_frontend *zl10039_attach(struct dvb_frontend *fe,
    					u8 i2c_addr,
    					struct i2c_adapter *i2c);
    static inline struct dvb_frontend *zl10039_attach(struct dvb_frontend *fe,
    					u8 i2c_addr,
    					struct i2c_adapter *i2c)
    {
    	printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
    	return NULL;
    }
    
    The above code, with the .config file used, was evoluting to FALSE
    (instead of TRUE as it should be, as CONFIG_DVB_ZL10039 is 'm'),
    and were adding the static inline code at saa7134-dvb, instead
    of the external call. So, while it weren't producing any compilation
    error, the code weren't working either.
    
    So, as the overhead for using CONFIG_MEDIA_ATTACH is minimal, just
    enable it, if MODULES is defined.
    Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
    bb69ee27
Kconfig 7.11 KB