tree: https://github.com/l1k/linux rs485_fixes head: 5545dfa04324da44dd044c03e7c13a7d6066f47e commit: 5545dfa04324da44dd044c03e7c13a7d6066f47e [8/8] serial: 8250: 8250_omap: Avoid rs485 RTS glitch on set_termios config: riscv-buildonly-randconfig-r002-20220105 (https://download.01.org/0day-ci/archive/20220105/202201051919.S2AM5Jqq-lkp@intel.com/config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d5b6e30ed3acad794dd0aec400e617daffc6cc3d) 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 # install riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://github.com/l1k/linux/commit/5545dfa04324da44dd044c03e7c13a7d6066f47e git remote add l1k https://github.com/l1k/linux git fetch --no-tags l1k rs485_fixes git checkout 5545dfa04324da44dd044c03e7c13a7d6066f47e # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/tty/serial/8250/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): In file included from drivers/tty/serial/8250/8250_omap.c:13: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:136: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from drivers/tty/serial/8250/8250_omap.c:13: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:136: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from drivers/tty/serial/8250/8250_omap.c:13: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:136: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:1024:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; ~~~~~~~~~~ ^ >> drivers/tty/serial/8250/8250_omap.c:327:2: error: implicit declaration of function 'serial8250_set_mctrl' [-Werror,-Wimplicit-function-declaration] serial8250_set_mctrl(&up->port, up->port.mctrl); ^ drivers/tty/serial/8250/8250_omap.c:327:2: note: did you mean 'serial8250_do_set_mctrl'? include/linux/serial_8250.h:167:13: note: 'serial8250_do_set_mctrl' declared here extern void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl); ^ 7 warnings and 1 error generated. vim +/serial8250_set_mctrl +327 drivers/tty/serial/8250/8250_omap.c 290 291 static void omap8250_restore_regs(struct uart_8250_port *up) 292 { 293 struct omap8250_priv *priv = up->port.private_data; 294 struct uart_8250_dma *dma = up->dma; 295 296 if (dma && dma->tx_running) { 297 /* 298 * TCSANOW requests the change to occur immediately however if 299 * we have a TX-DMA operation in progress then it has been 300 * observed that it might stall and never complete. Therefore we 301 * delay DMA completes to prevent this hang from happen. 302 */ 303 priv->delayed_restore = 1; 304 return; 305 } 306 307 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 308 serial_out(up, UART_EFR, UART_EFR_ECB); 309 310 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); 311 serial8250_out_MCR(up, serial8250_in_MCR(up) | UART_MCR_TCRTLR); 312 serial_out(up, UART_FCR, up->fcr); 313 314 omap8250_update_scr(up, priv); 315 316 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 317 318 serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_RESTORE(16) | 319 OMAP_UART_TCR_HALT(52)); 320 serial_out(up, UART_TI752_TLR, 321 TRIGGER_TLR_MASK(priv->tx_trigger) << UART_TI752_TLR_TX | 322 TRIGGER_TLR_MASK(priv->rx_trigger) << UART_TI752_TLR_RX); 323 324 serial_out(up, UART_LCR, 0); 325 326 /* drop TCR + TLR access, we setup XON/XOFF later */ > 327 serial8250_set_mctrl(&up->port, up->port.mctrl); 328 serial_out(up, UART_IER, up->ier); 329 330 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 331 serial_dl_write(up, priv->quot); 332 333 serial_out(up, UART_EFR, priv->efr); 334 335 /* Configure flow control */ 336 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 337 serial_out(up, UART_XON1, priv->xon); 338 serial_out(up, UART_XOFF1, priv->xoff); 339 340 serial_out(up, UART_LCR, up->lcr); 341 342 omap8250_update_mdr1(up, priv); 343 } 344 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org