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| author | David Woodhouse <dwmw2@infradead.org> | 2007-05-17 14:27:39 +0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-17 05:25:49 -0700 |
| commit | b5b82df6f461e66af821bff5b51f336af92d96b6 (patch) | |
| tree | b0a782f0f97419082d9c40de7fcc9fd5fd560be2 /drivers/serial/8250.c | |
| parent | c97a9e10eaee328e6eea9f76acf7bacd7d48ef56 (diff) | |
| download | linux-b5b82df6f461e66af821bff5b51f336af92d96b6.tar.gz linux-b5b82df6f461e66af821bff5b51f336af92d96b6.tar.bz2 linux-b5b82df6f461e66af821bff5b51f336af92d96b6.zip | |
NS16550A: Restore HS settings in EXCR2 on resume
After a suspend/resume cycle, the UART may have been reset into
low-speed mode -- either because it's actually been reset, or because
the firmware pokes at the old-style divisor registers. If we detected it
as a NS16550A SuperIO chip in the first place and set baud_base to
921600, then we should do so again in the resume path.
This patch adds that code to serial8250_resume_port(), and also makes
serial8250_resume() actually call serial8250_resume_port() for each port
instead of just calling uart_resume_port() directly. And thus fixes
serial port operation after suspend/resume.
It also fixes a bogus comment where we write the EXCR2 register with a
comment saying /* EXCR1 */
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/serial/8250.c')
| -rw-r--r-- | drivers/serial/8250.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 48e259a0167d..c84dab083a85 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -894,7 +894,7 @@ static void autoconfig_16550a(struct uart_8250_port *up) quot = serial_dl_read(up); quot <<= 3; - status1 = serial_in(up, 0x04); /* EXCR1 */ + status1 = serial_in(up, 0x04); /* EXCR2 */ status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */ status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ serial_outp(up, 0x04, status1); @@ -2617,7 +2617,22 @@ void serial8250_suspend_port(int line) */ void serial8250_resume_port(int line) { - uart_resume_port(&serial8250_reg, &serial8250_ports[line].port); + struct uart_8250_port *up = &serial8250_ports[line]; + + if (up->capabilities & UART_NATSEMI) { + unsigned char tmp; + + /* Ensure it's still in high speed mode */ + serial_outp(up, UART_LCR, 0xE0); + + tmp = serial_in(up, 0x04); /* EXCR2 */ + tmp &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */ + tmp |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ + serial_outp(up, 0x04, tmp); + + serial_outp(up, UART_LCR, 0); + } + uart_resume_port(&serial8250_reg, &up->port); } /* @@ -2694,7 +2709,7 @@ static int serial8250_resume(struct platform_device *dev) struct uart_8250_port *up = &serial8250_ports[i]; if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) - uart_resume_port(&serial8250_reg, &up->port); + serial8250_resume_port(i); } return 0; |