Hello qipeng.zha, The patch 4de60970abf9: "gpiolib: translate pin number in GPIO ACPI callbacks" from Mar 11, 2015, leads to the following static checker warning: drivers/gpio/gpiolib-acpi.c:559 acpi_gpio_adr_space_handler() warn: unsigned 'pin' is never less than zero. drivers/gpio/gpiolib-acpi.c 550 551 length = min(agpio->pin_table_length, (u16)(pin_index + bits)); 552 for (i = pin_index; i < length; ++i) { 553 unsigned pin = agpio->pin_table[i]; ^^^^^^^^^^^^^^^^^^^^^^^^^ "pin" is already assigned. 554 struct acpi_gpio_connection *conn; 555 struct gpio_desc *desc; 556 bool found; 557 558 pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin); 559 if (pin < 0) { ^^^^^^^ Error checking doesn't work. 560 status = AE_BAD_PARAMETER; 561 goto out; 562 } 563 564 mutex_lock(&achip->conn_lock); regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html