Hi Wojciech,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on linus/master v5.16-rc1 next-20211118]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Wojciech-Bartczak/mmc-cavium-Fix-MMC-supply-switching-for-cards/20211118-063028
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: ia64-buildonly-randconfig-r005-20211119 (attached as .config)
compiler: ia64-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/1a0194dde9d7f7c97c8257103835b04cbaf50f3b
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Wojciech-Bartczak/mmc-cavium-Fix-MMC-supply-switching-for-cards/20211118-063028
        git checkout 1a0194dde9d7f7c97c8257103835b04cbaf50f3b
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=ia64 SHELL=/bin/bash drivers/mmc/host/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All warnings (new ones prefixed by >>):

quoted

drivers/mmc/host/cavium.c:205: warning: expecting prototype for pre_switch(). Prototype was for switch_vqmmc() instead

vim +205 drivers/mmc/host/cavium.c

ba3869ff32e4a6 Jan Glauber       2017-03-30  195  
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  196  /**
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  197   * pre_switch - Switch voltage regulators
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  198   * @prev: Current slot, can be NULL
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  199   * @next: Next slot
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  200   *
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  201   * Switch between regulators used by slots. This call has to be done
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  202   * after call to pre_switch().
ba3869ff32e4a6 Jan Glauber       2017-03-30  203   */
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  204  static void switch_vqmmc(struct cvm_mmc_slot *prev, struct cvm_mmc_slot *next)
ba3869ff32e4a6 Jan Glauber       2017-03-30 @205  {
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  206  	bool same_vqmmc = false;
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  207  	struct regulator *next_vqmmc;
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  208  	struct regulator *prev_vqmmc;
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  209  
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  210  	next_vqmmc = next->mmc->supply.vqmmc;
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  211  	if (prev) {
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  212  		prev_vqmmc = prev->mmc->supply.vqmmc;
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  213  		/* Prev slot and next slot share vqmmc? */
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  214  		same_vqmmc = prev_vqmmc == next_vqmmc;
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  215  		/* Disable old regulator, if not the same */
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  216  		if (!same_vqmmc && !IS_ERR_OR_NULL(prev_vqmmc))
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  217  			regulator_disable(prev_vqmmc);
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  218  	}
ba3869ff32e4a6 Jan Glauber       2017-03-30  219  
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  220  	/* Enable regulator for next slot */
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  221  	if (!same_vqmmc && !IS_ERR_OR_NULL(next_vqmmc)) {
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  222  		int ret;
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  223  
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  224  		ret = regulator_enable(next_vqmmc);
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  225  		if (ret)
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  226  			dev_err(mmc_classdev(next->mmc),
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  227  				"Can't enable vqmmc, error (%d)!\n", ret);
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  228  	}
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  229  }
1a0194dde9d7f7 Wojciech Bartczak 2021-11-17  230  

---
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