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| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2017-05-24 22:38:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-09 10:50:19 +0300 |
| commit | aa6b517e74512ef8373ff66a40f4925f9b6edab6 (patch) | |
| tree | d80d8c47cc9ad73fd15d6f690c1d22488f3ad9d1 /drivers | |
| parent | 23fb8f797e6bee5c39b43e6f4c6f15203ee8ea14 (diff) | |
| download | linux-aa6b517e74512ef8373ff66a40f4925f9b6edab6.tar.xz | |
serial: imx: ensure UCR3 and UFCR are setup correctly
commit 6df765dca378bddf994cfd2044acafa501bd800f upstream.
Commit e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and
RI irqs to be off") has a flaw: While UCR3 and UFCR were modified using
read-modify-write before it switched to write register values
independent of the previous state. That's a good idea in principle (and
that's why I did it) but needs more care.
This patch reinstates read-modify-write for UFCR and for UCR3 ensures
that RXDMUXSEL and ADNIMP are set for post imx1.
Fixes: e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Mika Penttilä <mika.penttila@nextfour.com>
Tested-by: Mika Penttilä <mika.penttila@nextfour.com>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Tested-by: Steve Twiss <stwiss.opensource@diasemi.com>
Cc: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/imx.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index f575a33974fa..ecadc27eea48 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2145,7 +2145,9 @@ static int serial_imx_probe(struct platform_device *pdev) * and DCD (when they are outputs) or enables the respective * irqs. So set this bit early, i.e. before requesting irqs. */ - writel(UFCR_DCEDTE, sport->port.membase + UFCR); + reg = readl(sport->port.membase + UFCR); + if (!(reg & UFCR_DCEDTE)) + writel(reg | UFCR_DCEDTE, sport->port.membase + UFCR); /* * Disable UCR3_RI and UCR3_DCD irqs. They are also not @@ -2156,7 +2158,15 @@ static int serial_imx_probe(struct platform_device *pdev) sport->port.membase + UCR3); } else { - writel(0, sport->port.membase + UFCR); + unsigned long ucr3 = UCR3_DSR; + + reg = readl(sport->port.membase + UFCR); + if (reg & UFCR_DCEDTE) + writel(reg & ~UFCR_DCEDTE, sport->port.membase + UFCR); + + if (!is_imx1_uart(sport)) + ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP; + writel(ucr3, sport->port.membase + UCR3); } clk_disable_unprepare(sport->clk_ipg); |