[PATCH v6 2/7] mux: Add helper functions for getting optional and selected mux-state

[Dan Carpenter]

Hi Josua,

kernel test robot noticed the following build warnings:

url:    https://github.com/intel-lab-lkp/linux/commits/Josua-Mayer/phy-can-transceiver-rename-temporary-helper-function-to-avoid-conflict/20260121-173607
base:   8f0b4cce4481fb22653697cced8d0d04027cb1e8
patch link:    https://lore.kernel.org/r/20260121-rz-sdio-mux-v6-2-38aa39527928%40solid-run.com
patch subject: [PATCH v6 2/7] mux: Add helper functions for getting optional and selected mux-state
config: arm64-randconfig-r073-20260121 (https://download.01.org/0day-ci/archive/20260122/202601221036.J0kR78Uw-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 8.5.0
smatch version: v0.5.0-8985-g2614ff1a

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
| Closes: https://lore.kernel.org/r/202601221036.J0kR78Uw-lkp@intel.com/

New smatch warnings:
drivers/mux/core.c:776 __devm_mux_state_get() warn: passing zero to 'PTR_ERR'
drivers/mux/core.c:796 __devm_mux_state_get() warn: passing zero to 'ERR_PTR'

Old smatch warnings:
drivers/mux/core.c:722 mux_state_get() warn: passing zero to 'ERR_CAST'

vim +/PTR_ERR +776 drivers/mux/core.c

0610cc3159b786 Josua Mayer       2026-01-21  761  static struct mux_state *__devm_mux_state_get(struct device *dev, const char *mux_name,
0610cc3159b786 Josua Mayer       2026-01-21  762  					      bool optional,
0610cc3159b786 Josua Mayer       2026-01-21  763  					      int (*init)(struct mux_state *mstate),
0610cc3159b786 Josua Mayer       2026-01-21  764  					      int (*exit)(struct mux_state *mstate))
0610cc3159b786 Josua Mayer       2026-01-21  765  {
0610cc3159b786 Josua Mayer       2026-01-21  766  	struct devm_mux_state_state *devm_state;
0610cc3159b786 Josua Mayer       2026-01-21  767  	struct mux_state *mstate;
0610cc3159b786 Josua Mayer       2026-01-21  768  	int ret;
84564481bc4520 Aswath Govindraju 2022-01-07  769  
0610cc3159b786 Josua Mayer       2026-01-21  770  	devm_state = devres_alloc(devm_mux_state_release, sizeof(*devm_state), GFP_KERNEL);
0610cc3159b786 Josua Mayer       2026-01-21  771  	if (!devm_state)
0610cc3159b786 Josua Mayer       2026-01-21  772  		return ERR_PTR(-ENOMEM);
0610cc3159b786 Josua Mayer       2026-01-21  773  
0610cc3159b786 Josua Mayer       2026-01-21  774  	mstate = mux_state_get(dev, mux_name, optional);
0610cc3159b786 Josua Mayer       2026-01-21  775  	if (IS_ERR_OR_NULL(mstate)) {

Please, change this to if (IS_ERR(mstate)) {.  The mux_state_get() never
returns NULL.  I have written a blog about functions which return both
error pointers and NULL.

https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/

0610cc3159b786 Josua Mayer       2026-01-21 @776  		ret = PTR_ERR(mstate);
0610cc3159b786 Josua Mayer       2026-01-21  777  		goto err_mux_state_get;
0610cc3159b786 Josua Mayer       2026-01-21  778  	}
0610cc3159b786 Josua Mayer       2026-01-21  779  
0610cc3159b786 Josua Mayer       2026-01-21  780  	if (init) {
0610cc3159b786 Josua Mayer       2026-01-21  781  		ret = init(mstate);
0610cc3159b786 Josua Mayer       2026-01-21  782  		if (ret)
0610cc3159b786 Josua Mayer       2026-01-21  783  			goto err_mux_state_init;
0610cc3159b786 Josua Mayer       2026-01-21  784  	}
0610cc3159b786 Josua Mayer       2026-01-21  785  
0610cc3159b786 Josua Mayer       2026-01-21  786  	devm_state->mstate = mstate;
0610cc3159b786 Josua Mayer       2026-01-21  787  	devm_state->exit = exit;
0610cc3159b786 Josua Mayer       2026-01-21  788  	devres_add(dev, devm_state);
0610cc3159b786 Josua Mayer       2026-01-21  789  
0610cc3159b786 Josua Mayer       2026-01-21  790  	return mstate;
0610cc3159b786 Josua Mayer       2026-01-21  791  
0610cc3159b786 Josua Mayer       2026-01-21  792  err_mux_state_init:
84564481bc4520 Aswath Govindraju 2022-01-07  793  	mux_state_put(mstate);
0610cc3159b786 Josua Mayer       2026-01-21  794  err_mux_state_get:
0610cc3159b786 Josua Mayer       2026-01-21  795  	devres_free(devm_state);
0610cc3159b786 Josua Mayer       2026-01-21 @796  	return ERR_PTR(ret);
84564481bc4520 Aswath Govindraju 2022-01-07  797  }

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