[tty:tty-testing 11/22] drivers/tty/serial/sc16is7xx.c:596:2: error: call to undeclared function 'sc16is7xx_efr_lock'; ISO C99 and later do not support implicit function declarations

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
head:   cdca3a77b423691b0e3780653642cd5b31de8bd8
commit: 5a91e16ba44d9850088278ebe209b5c533f87cb8 [11/22] serial: sc16is7xx: define common register access function
config: x86_64-buildonly-randconfig-001-20251022 (https://download.01.org/0day-ci/archive/20251022/202510222116.kkZML444-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251022/202510222116.kkZML444-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510222116.kkZML444-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/tty/serial/sc16is7xx.c:596:2: error: call to undeclared function 'sc16is7xx_efr_lock'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     596 |         sc16is7xx_efr_lock(port);
         |         ^
   drivers/tty/serial/sc16is7xx.c:596:2: note: did you mean 'sc16is7xx_regs_lock'?
   drivers/tty/serial/sc16is7xx.c:441:13: note: 'sc16is7xx_regs_lock' declared here
     441 | static void sc16is7xx_regs_lock(struct uart_port *port, u8 register_set)
         |             ^
>> drivers/tty/serial/sc16is7xx.c:600:2: error: call to undeclared function 'sc16is7xx_efr_unlock'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     600 |         sc16is7xx_efr_unlock(port);
         |         ^
   2 errors generated.


vim +/sc16is7xx_efr_lock +596 drivers/tty/serial/sc16is7xx.c

dbf4ab821804df Hugo Villeneuve 2023-12-11  572  
8492bd91aa0559 Hugo Villeneuve 2024-04-30  573  /*
8492bd91aa0559 Hugo Villeneuve 2024-04-30  574   * Configure programmable baud rate generator (divisor) according to the
8492bd91aa0559 Hugo Villeneuve 2024-04-30  575   * desired baud rate.
8492bd91aa0559 Hugo Villeneuve 2024-04-30  576   *
8492bd91aa0559 Hugo Villeneuve 2024-04-30  577   * From the datasheet, the divisor is computed according to:
8492bd91aa0559 Hugo Villeneuve 2024-04-30  578   *
8492bd91aa0559 Hugo Villeneuve 2024-04-30  579   *              XTAL1 input frequency
8492bd91aa0559 Hugo Villeneuve 2024-04-30  580   *             -----------------------
8492bd91aa0559 Hugo Villeneuve 2024-04-30  581   *                    prescaler
8492bd91aa0559 Hugo Villeneuve 2024-04-30  582   * divisor = ---------------------------
8492bd91aa0559 Hugo Villeneuve 2024-04-30  583   *            baud-rate x sampling-rate
8492bd91aa0559 Hugo Villeneuve 2024-04-30  584   */
dfeae619d781de Jon Ringle      2014-04-24  585  static int sc16is7xx_set_baud(struct uart_port *port, int baud)
dfeae619d781de Jon Ringle      2014-04-24  586  {
8492bd91aa0559 Hugo Villeneuve 2024-04-30  587  	unsigned int prescaler = 1;
dfeae619d781de Jon Ringle      2014-04-24  588  	unsigned long clk = port->uartclk, div = clk / 16 / baud;
dfeae619d781de Jon Ringle      2014-04-24  589  
2e57cefc447765 Hugo Villeneuve 2023-12-21  590  	if (div >= BIT(16)) {
8492bd91aa0559 Hugo Villeneuve 2024-04-30  591  		prescaler = 4;
8492bd91aa0559 Hugo Villeneuve 2024-04-30  592  		div /= prescaler;
dfeae619d781de Jon Ringle      2014-04-24  593  	}
dfeae619d781de Jon Ringle      2014-04-24  594  
dfeae619d781de Jon Ringle      2014-04-24  595  	/* Enable enhanced features */
0c84bea0cabc4e Hugo Villeneuve 2023-12-21 @596  	sc16is7xx_efr_lock(port);
c112653b89e0ce Lech Perczak    2022-02-21  597  	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
c112653b89e0ce Lech Perczak    2022-02-21  598  			      SC16IS7XX_EFR_ENABLE_BIT,
dfeae619d781de Jon Ringle      2014-04-24  599  			      SC16IS7XX_EFR_ENABLE_BIT);
0c84bea0cabc4e Hugo Villeneuve 2023-12-21 @600  	sc16is7xx_efr_unlock(port);
30ec514d440cf2 Phil Elwell     2018-09-12  601  
8492bd91aa0559 Hugo Villeneuve 2024-04-30  602  	/* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
dfeae619d781de Jon Ringle      2014-04-24  603  	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
dfeae619d781de Jon Ringle      2014-04-24  604  			      SC16IS7XX_MCR_CLKSEL_BIT,
8492bd91aa0559 Hugo Villeneuve 2024-04-30  605  			      prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT);
dfeae619d781de Jon Ringle      2014-04-24  606  
5a91e16ba44d98 Hugo Villeneuve 2025-10-02  607  	/* Access special register set (DLL/DLH) */
5a91e16ba44d98 Hugo Villeneuve 2025-10-02  608  	sc16is7xx_regs_lock(port, SC16IS7XX_LCR_REG_SET_SPECIAL);
dfeae619d781de Jon Ringle      2014-04-24  609  
dfeae619d781de Jon Ringle      2014-04-24  610  	/* Write the new divisor */
dfeae619d781de Jon Ringle      2014-04-24  611  	sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
dfeae619d781de Jon Ringle      2014-04-24  612  	sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
dfeae619d781de Jon Ringle      2014-04-24  613  
5a91e16ba44d98 Hugo Villeneuve 2025-10-02  614  	/* Restore access to general register set */
5a91e16ba44d98 Hugo Villeneuve 2025-10-02  615  	sc16is7xx_regs_unlock(port);
7d3b793faaab13 Hugo Villeneuve 2024-07-23  616  
8492bd91aa0559 Hugo Villeneuve 2024-04-30  617  	return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
dfeae619d781de Jon Ringle      2014-04-24  618  }
dfeae619d781de Jon Ringle      2014-04-24  619  

:::::: The code at line 596 was first introduced by commit
:::::: 0c84bea0cabc4e2b98a3de88eeb4ff798931f056 serial: sc16is7xx: refactor EFR lock

:::::: TO: Hugo Villeneuve <hvilleneuve@dimonoff.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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