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| author | Stefan-gabriel Mirea <stefan-gabriel.mirea@nxp.com> | 2019-09-18 21:45:49 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-04 16:02:28 +0300 |
| commit | 9050079719021776e48437827eb9d5986b6e45d4 (patch) | |
| tree | 87393e2b295a150a261933f3039e37fa05330636 /drivers/tty/serial | |
| parent | 392fb8df528b97a06e19312772afd38aec542b96 (diff) | |
| download | linux-9050079719021776e48437827eb9d5986b6e45d4.tar.xz | |
tty: serial: linflexuart: Fix magic SysRq handling
Following an incorrect indentation reported to me by Dan Carpenter, I
noticed that the SysRq lines were inherited from the lpuart driver[1] (note
how the 'continue' is aligned to 'sport->port.sysrq = 0') and we have never
actually tested the SysRq support.
'sport->sysrq = 0' is not necessary neither before nor after 'continue',
because sysrq will already be 0 after uart_handle_sysrq_char() will finish.
Also, since the LINFlexD driver never called uart_handle_break(), sysrq
would have never been set to a nonzero value, so uart_handle_sysrq_char()
was not going to do anything.
Break conditions are detected based on a null data byte along with a
framing error (stop bit sampled to 0).
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/tty/serial/fsl_lpuart.c?h=b3e3bf2ef2c74f5ce5c19510edbbb9bfc1d249c2#n659
Fixes: 09864c1cdf5c ("tty: serial: Add linflexuart driver for S32V234")
Signed-off-by: Stefan-Gabriel Mirea <stefan-gabriel.mirea@nxp.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20190918184439.7465-1-stefan-gabriel.mirea@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/fsl_linflexuart.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c index 68d74f2b5106..a32f0d2afd59 100644 --- a/drivers/tty/serial/fsl_linflexuart.c +++ b/drivers/tty/serial/fsl_linflexuart.c @@ -3,7 +3,7 @@ * Freescale linflexuart serial port driver * * Copyright 2012-2016 Freescale Semiconductor, Inc. - * Copyright 2017-2018 NXP + * Copyright 2017-2019 NXP */ #if defined(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE) && \ @@ -246,12 +246,14 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id) struct tty_port *port = &sport->state->port; unsigned long flags, status; unsigned char rx; + bool brk; spin_lock_irqsave(&sport->lock, flags); status = readl(sport->membase + UARTSR); while (status & LINFLEXD_UARTSR_RMB) { rx = readb(sport->membase + BDRM); + brk = false; flg = TTY_NORMAL; sport->icount.rx++; @@ -261,8 +263,11 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id) status |= LINFLEXD_UARTSR_SZF; if (status & LINFLEXD_UARTSR_BOF) status |= LINFLEXD_UARTSR_BOF; - if (status & LINFLEXD_UARTSR_FEF) + if (status & LINFLEXD_UARTSR_FEF) { + if (!rx) + brk = true; status |= LINFLEXD_UARTSR_FEF; + } if (status & LINFLEXD_UARTSR_PE) status |= LINFLEXD_UARTSR_PE; } @@ -271,13 +276,15 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id) sport->membase + UARTSR); status = readl(sport->membase + UARTSR); - if (uart_handle_sysrq_char(sport, (unsigned char)rx)) - continue; - + if (brk) { + uart_handle_break(sport); + } else { #ifdef SUPPORT_SYSRQ - sport->sysrq = 0; + if (uart_handle_sysrq_char(sport, (unsigned char)rx)) + continue; #endif - tty_insert_flip_char(port, rx, flg); + tty_insert_flip_char(port, rx, flg); + } } spin_unlock_irqrestore(&sport->lock, flags); |