Hi Greg, This patch set introduces tunable RX interrupt trigger I/F for 8250 serials. I used Greg's patch(*1) as 1st patch in this version, and applied 2nd patch of previous version. Would you review this patch set? Thanks! Note: I cleaned up Greg's patch as follows: - Delete extra line break - Use kcalloc instead of kmalloc - sizeof(struct attribute_group *) => sizeof(**uport->tty_groups) *1: https://lkml.org/lkml/2014/7/12/177 <Change log> Changes in V9: [2/2] - Use attr_group instead of dev_spec_attr_group of uart_port structure Changes in V8: - Split V7's patch up into 2 patches Changes in V7: - Add Documentation - Change I/F name from rx_int_trig to rx_trig_bytes because the name rx_int_trig is hard to understand how users specify the value Changes in V6: - Move FCR_RX_TRIG_* definition in 8250.h to include/uapi/linux/serial_reg.h, rename those to UART_FCR_R_TRIG_*, and use UART_FCR_TRIGGER_MASK to UART_FCR_R_TRIG_BITS() - Change following function names: convert_fcr2val() => fcr_get_rxtrig_bytes() convert_val2rxtrig() => bytes_to_fcr_rxtrig() - Fix typo in serial8250_do_set_termios() - Delete the verbose error message pr_info() in bytes_to_fcr_rxtrig() - Rename *rx_int_trig/rx_trig* to *rxtrig* for several functions or variables (but UI remains rx_int_trig) - Change the meaningless variable name 'val' to 'bytes' following functions: fcr_get_rxtrig_bytes(), bytes_to_fcr_rxtrig(), do_set_rxtrig(), do_serial8250_set_rxtrig(), and serial8250_set_attr_rxtrig() - Use up->fcr in order to get rxtrig_bytes instead of rx_trig_raw in fcr_get_rxtrig_bytes() - Use conf_type->rxtrig_bytes[0] instead of switch statement for support check in register_dev_spec_attr_grp() - Delete the checking whether a user changed FCR or not when minimum buffer is needed in serial8250_do_set_termios() Changes in V5.1: - Fix FCR_RX_TRIG_MAX_STATE definition Changes in V5: - Support Tegra, 16650V2, 16654, and 16750 - Store default FCR value to up->fcr when the port is first created - Add rx_trig_byte[] in uart_config[] for each device and use rx_trig_byte[] in convert_fcr2val() and convert_val2rxtrig() Changes in V4: - Introduce fifo_bug flag in uart_8250_port structure This is enabled only when parity is enabled and UART_BUG_PARITY is enabled for up->bugs. If this flag is enabled, user cannot set RX trigger. - Return -EOPNOTSUPP when it does not support device at convert_fcr2val() and at convert_val2rxtrig() - Set the nearest lower RX trigger when users input a meaningless value at convert_val2rxtrig() - Check whether p->fcr is existing at serial8250_clear_and_reinit_fifos() - Set fcr = up->fcr in the begging of serial8250_do_set_termios() Changes in V3: - Change I/F from ioctl(2) to sysfs(rx_int_trig) Changed in V2: - Use _IOW for TIOCSFIFORTRIG definition - Pass the interrupt trigger value itself --- Greg Kroah-Hartman (1): Serial: allow port drivers to have a default attribute group Yoshihiro YUNOMAE (1): serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers Documentation/ABI/testing/sysfs-tty | 16 +++ drivers/tty/serial/8250/8250.h | 2 drivers/tty/serial/8250/8250_core.c | 173 ++++++++++++++++++++++++++++++++--- drivers/tty/serial/serial_core.c | 24 +++-- include/linux/serial_8250.h | 2 include/linux/serial_core.h | 2 include/uapi/linux/serial_reg.h | 5 + 7 files changed, 202 insertions(+), 22 deletions(-) -- Yoshihiro YUNOMAE Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: yoshihiro.yunomae.ez@xxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
