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| author | Daniel Thompson <daniel.thompson@linaro.org> | 2014-10-28 09:28:07 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-06 14:57:23 -0800 |
| commit | f968ef34945f8e606c5d98ff330a5903785ea76a (patch) | |
| tree | a2feca9ae84c3143c074c9a32fd05c13f88a3e0d /drivers/tty | |
| parent | 97f754710304382607417c700476007443cd96a4 (diff) | |
| download | linux-stable-f968ef34945f8e606c5d98ff330a5903785ea76a.tar.gz linux-stable-f968ef34945f8e606c5d98ff330a5903785ea76a.tar.bz2 linux-stable-f968ef34945f8e606c5d98ff330a5903785ea76a.zip | |
serial: imx: clean up imx_poll_put_char()
imx_put_poll_char() has been simplified to remove the code to disable
interrupts. The present code can corrupt register state when re-entered
from FIQ handler.
Switch to _relaxed() MMIO functions (which are safe for polled I/O and
needed to avoid taking spin locks).
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Huang Shijie <b32955@freescale.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/imx.c | 24 |
1 files changed, 5 insertions, 19 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index d2e6cf5a1ab8..8d61aa98b932 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1457,42 +1457,28 @@ imx_verify_port(struct uart_port *port, struct serial_struct *ser) #if defined(CONFIG_CONSOLE_POLL) static int imx_poll_get_char(struct uart_port *port) { - if (!(readl(port->membase + USR2) & USR2_RDR)) + if (!(readl_relaxed(port->membase + USR2) & USR2_RDR)) return NO_POLL_CHAR; - return readl(port->membase + URXD0) & URXD_RX_DATA; + return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA; } static void imx_poll_put_char(struct uart_port *port, unsigned char c) { - struct imx_port_ucrs old_ucr; unsigned int status; - /* save control registers */ - imx_port_ucrs_save(port, &old_ucr); - - /* disable interrupts */ - writel(UCR1_UARTEN, port->membase + UCR1); - writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI), - port->membase + UCR2); - writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN), - port->membase + UCR3); - /* drain */ do { - status = readl(port->membase + USR1); + status = readl_relaxed(port->membase + USR1); } while (~status & USR1_TRDY); /* write */ - writel(c, port->membase + URTX0); + writel_relaxed(c, port->membase + URTX0); /* flush */ do { - status = readl(port->membase + USR2); + status = readl_relaxed(port->membase + USR2); } while (~status & USR2_TXDC); - - /* restore control registers */ - imx_port_ucrs_restore(port, &old_ucr); } #endif |