The infamous low_latency behaviour of tty_flip_buffer_push(), which meant that data could be pushed to the line discipline immediately instead of being deferred to a work queue, was finally removed in 2014. Since then there's no need for drivers to keep hacks to temporarily drop the port lock during receive processing but this pattern has been reproduced in later added drivers nonetheless. Note that several of these workarounds were added by a series posted in 2013, which ended up being merged despite having completely nonsensical commit messages. As it turned out, it was just the RT patch set which effectively enabled the low_latency flag for serial drivers that did not handle it. There's of course nothing wrong releasing the port lock before calling tty_flip_buffer_push(), and some drivers still do after this series, but let's get rid of the completely unnecessary unlock-and-reacquire pattern. Johan Johan Hovold (26): tty: mxser: drop low-latency workaround serial: altera_jtaguart: drop low-latency workaround serial: altera_uart: drop low-latency workaround serial: amba-pl010: drop low-latency workaround serial: amba-pl011: drop low-latency workaround serial: apbuart: drop low-latency workaround serial: ar933x: drop low-latency workaround serial: arc_uart: drop low-latency workaround serial: atmel_serial: drop low-latency workaround serial: bcm63xx: drop low-latency workaround serial: icom: drop low-latency workaround serial: lpc32xx_hs: drop low-latency workaround serial: mcf: drop low-latency workaround serial: meson: drop low-latency workaround serial: mpc52xx_uart: drop low-latency workaround serial: msm_serial: drop low-latency workaround serial: owl: drop low-latency workaround serial: rda: drop low-latency workaround serial: rp2: drop low-latency workaround serial: sa1100: drop low-latency workaround serial: txx9: drop low-latency workaround serial: sifive: drop low-latency workaround serial: sunsu: drop low-latency workaround serial: timbuart: drop low-latency workaround serial: vt8500: drop low-latency workaround serial: xilinx_uartps: drop low-latency workaround drivers/tty/mxser.c | 7 ------- drivers/tty/serial/altera_jtaguart.c | 2 -- drivers/tty/serial/altera_uart.c | 2 -- drivers/tty/serial/amba-pl010.c | 2 -- drivers/tty/serial/amba-pl011.c | 2 -- drivers/tty/serial/apbuart.c | 2 -- drivers/tty/serial/ar933x_uart.c | 2 -- drivers/tty/serial/arc_uart.c | 2 -- drivers/tty/serial/atmel_serial.c | 18 ------------------ drivers/tty/serial/bcm63xx_uart.c | 2 -- drivers/tty/serial/icom.c | 2 -- drivers/tty/serial/lpc32xx_hs.c | 2 -- drivers/tty/serial/mcf.c | 2 -- drivers/tty/serial/meson_uart.c | 2 -- drivers/tty/serial/mpc52xx_uart.c | 2 -- drivers/tty/serial/msm_serial.c | 4 ---- drivers/tty/serial/owl-uart.c | 2 -- drivers/tty/serial/rda-uart.c | 2 -- drivers/tty/serial/rp2.c | 2 -- drivers/tty/serial/sa1100.c | 2 -- drivers/tty/serial/serial_txx9.c | 4 ++-- drivers/tty/serial/sifive.c | 2 -- drivers/tty/serial/sunsu.c | 4 ---- drivers/tty/serial/timbuart.c | 2 -- drivers/tty/serial/vt8500_serial.c | 2 -- drivers/tty/serial/xilinx_uartps.c | 3 +-- 26 files changed, 3 insertions(+), 77 deletions(-) -- 2.26.3
