Re: [PATCH v2 3/7] soc: qcom: add QCOM PBS driver

[Dan Carpenter]

Hi Anjelique,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Anjelique-Melendez/dt-bindings-soc-qcom-Add-qcom-pbs-bindings/20230726-034011
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20230725193423.25047-4-quic_amelende%40quicinc.com
patch subject: [PATCH v2 3/7] soc: qcom: add QCOM PBS driver
config: parisc-randconfig-m041-20230726 (https://download.01.org/0day-ci/archive/20230727/202307270539.1JVFQf6W-lkp@xxxxxxxxx/config)
compiler: hppa-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230727/202307270539.1JVFQf6W-lkp@xxxxxxxxx/reproduce)

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@xxxxxxxxx>
| Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
| Closes: https://lore.kernel.org/r/202307270539.1JVFQf6W-lkp@xxxxxxxxx/

smatch warnings:
drivers/soc/qcom/qcom-pbs.c:97 qcom_pbs_wait_for_ack() warn: should this be 'retries == -1'

vim +97 drivers/soc/qcom/qcom-pbs.c

c261225d90e1d3 Anjelique Melendez 2023-07-25   68  static int qcom_pbs_wait_for_ack(struct pbs_dev *pbs, u8 bit_pos)
c261225d90e1d3 Anjelique Melendez 2023-07-25   69  {
c261225d90e1d3 Anjelique Melendez 2023-07-25   70  	u16 retries = 2000, delay = 1000;
c261225d90e1d3 Anjelique Melendez 2023-07-25   71  	int ret;
c261225d90e1d3 Anjelique Melendez 2023-07-25   72  	u8 val;
c261225d90e1d3 Anjelique Melendez 2023-07-25   73  
c261225d90e1d3 Anjelique Melendez 2023-07-25   74  	while (retries--) {

Change this to while (--retries) {

c261225d90e1d3 Anjelique Melendez 2023-07-25   75  		ret = qcom_pbs_read(pbs, PBS_CLIENT_SCRATCH2, &val);
c261225d90e1d3 Anjelique Melendez 2023-07-25   76  		if (ret < 0)
c261225d90e1d3 Anjelique Melendez 2023-07-25   77  			return ret;
c261225d90e1d3 Anjelique Melendez 2023-07-25   78  
c261225d90e1d3 Anjelique Melendez 2023-07-25   79  		if (val == 0xFF) {
c261225d90e1d3 Anjelique Melendez 2023-07-25   80  			/* PBS error - clear SCRATCH2 register */
c261225d90e1d3 Anjelique Melendez 2023-07-25   81  			ret = qcom_pbs_write(pbs, PBS_CLIENT_SCRATCH2, 0);
c261225d90e1d3 Anjelique Melendez 2023-07-25   82  			if (ret < 0)
c261225d90e1d3 Anjelique Melendez 2023-07-25   83  				return ret;
c261225d90e1d3 Anjelique Melendez 2023-07-25   84  
c261225d90e1d3 Anjelique Melendez 2023-07-25   85  			dev_err(pbs->dev, "NACK from PBS for bit %u\n", bit_pos);
c261225d90e1d3 Anjelique Melendez 2023-07-25   86  			return -EINVAL;
c261225d90e1d3 Anjelique Melendez 2023-07-25   87  		}
c261225d90e1d3 Anjelique Melendez 2023-07-25   88  
c261225d90e1d3 Anjelique Melendez 2023-07-25   89  		if (val & BIT(bit_pos)) {
c261225d90e1d3 Anjelique Melendez 2023-07-25   90  			dev_dbg(pbs->dev, "PBS sequence for bit %u executed!\n", bit_pos);
c261225d90e1d3 Anjelique Melendez 2023-07-25   91  			break;
c261225d90e1d3 Anjelique Melendez 2023-07-25   92  		}
c261225d90e1d3 Anjelique Melendez 2023-07-25   93  
c261225d90e1d3 Anjelique Melendez 2023-07-25   94  		usleep_range(delay, delay + 100);
c261225d90e1d3 Anjelique Melendez 2023-07-25   95  	}
c261225d90e1d3 Anjelique Melendez 2023-07-25   96  
c261225d90e1d3 Anjelique Melendez 2023-07-25  @97  	if (!retries) {

Otherwise this check needs to be: "if (retries == USHRT_MAX)".

Btw, I really feel like people are generally better off declaring list
iterators as int whenever possible.  I have written a very rude blog
to that effect.
https://staticthinking.wordpress.com/2022/06/01/unsigned-int-i-is-stupid/

c261225d90e1d3 Anjelique Melendez 2023-07-25   98  		dev_err(pbs->dev, "Timeout for PBS ACK/NACK for bit %u\n", bit_pos);
c261225d90e1d3 Anjelique Melendez 2023-07-25   99  		return -ETIMEDOUT;
c261225d90e1d3 Anjelique Melendez 2023-07-25  100  	}
c261225d90e1d3 Anjelique Melendez 2023-07-25  101  
c261225d90e1d3 Anjelique Melendez 2023-07-25  102  	return 0;
c261225d90e1d3 Anjelique Melendez 2023-07-25  103  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki