Merge tag 'tty-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH: "Here is the large tty/serial patchset for 4.13-rc1. A lot of tty and serial driver updates are in here, along with some fixups for some __get/put_user usages that were reported. Nothing huge, just lots of development by a number of different developers, full details in the shortlog. All of these have been in linux-next for a while" * tag 'tty-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (71 commits) tty: serial: lpuart: add a more accurate baud rate calculation method tty: serial: lpuart: add earlycon support for imx7ulp tty: serial: lpuart: add imx7ulp support dt-bindings: serial: fsl-lpuart: add i.MX7ULP support tty: serial: lpuart: add little endian 32 bit register support tty: serial: lpuart: refactor lpuart32_{read|write} prototype tty: serial: lpuart: introduce lpuart_soc_data to represent SoC property serial: imx-serial - move DMA buffer configuration to DT serial: imx: Enable RTSD only when needed serial: imx: Remove unused members from imx_port struct serial: 8250: 8250_omap: Fix race b/w dma completion and RX timeout serial: 8250: Fix THRE flag usage for CAP_MINI tty/serial: meson_uart: update to stable bindings dt-bindings: serial: Add bindings for the Amlogic Meson UARTs serial: Delete dead code for CIR serial ports serial: sirf: make of_device_ids const serial/mpsc: switch to dma_alloc_attrs tty: serial: Add Actions Semi Owl UART earlycon dt-bindings: serial: Document Actions Semi Owl UARTs tty/serial: atmel: make the driver DT only ...
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@@ -491,6 +491,29 @@ static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
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tty_ldisc_debug(tty, "%p: closed\n", ld);
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}
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/**
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* tty_ldisc_failto - helper for ldisc failback
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* @tty: tty to open the ldisc on
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* @ld: ldisc we are trying to fail back to
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*
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* Helper to try and recover a tty when switching back to the old
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* ldisc fails and we need something attached.
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*/
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static int tty_ldisc_failto(struct tty_struct *tty, int ld)
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{
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struct tty_ldisc *disc = tty_ldisc_get(tty, ld);
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int r;
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if (IS_ERR(disc))
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return PTR_ERR(disc);
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tty->ldisc = disc;
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tty_set_termios_ldisc(tty, ld);
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if ((r = tty_ldisc_open(tty, disc)) < 0)
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tty_ldisc_put(disc);
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return r;
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}
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/**
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* tty_ldisc_restore - helper for tty ldisc change
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* @tty: tty to recover
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@@ -502,9 +525,6 @@ static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
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static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
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{
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struct tty_ldisc *new_ldisc;
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int r;
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/* There is an outstanding reference here so this is safe */
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old = tty_ldisc_get(tty, old->ops->num);
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WARN_ON(IS_ERR(old));
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@@ -512,17 +532,13 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
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tty_set_termios_ldisc(tty, old->ops->num);
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if (tty_ldisc_open(tty, old) < 0) {
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tty_ldisc_put(old);
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/* This driver is always present */
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new_ldisc = tty_ldisc_get(tty, N_TTY);
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if (IS_ERR(new_ldisc))
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panic("n_tty: get");
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tty->ldisc = new_ldisc;
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tty_set_termios_ldisc(tty, N_TTY);
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r = tty_ldisc_open(tty, new_ldisc);
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if (r < 0)
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panic("Couldn't open N_TTY ldisc for "
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"%s --- error %d.",
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tty_name(tty), r);
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/* The traditional behaviour is to fall back to N_TTY, we
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want to avoid falling back to N_NULL unless we have no
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choice to avoid the risk of breaking anything */
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if (tty_ldisc_failto(tty, N_TTY) < 0 &&
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tty_ldisc_failto(tty, N_NULL) < 0)
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panic("Couldn't open N_NULL ldisc for %s.",
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tty_name(tty));
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}
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}
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