From: Rick Bronson <rick@efn.org>
To: linux-omap@vger.kernel.org
Subject: Re: What happened to the serial console on BeagleBoard with 2.6.28-rc2?
Date: Wed, 29 Oct 2008 09:44:46 -0700 [thread overview]
Message-ID: <E1KvEA2-0002nH-8d@amazonia.comcast.net> (raw)
It looks like a race condition. Somehow the 8250 ends up with the
LSB of the baud rate register set to 0xff when it's supposed to be
0x1a. I'm still trying to figure it out :( The patch below gets it
working a little but there's still a problem after init runs. Note
that you will need to undef DEBUG_LL in the config.
Rick
--- linux-omap-2.6/drivers/serial/8250.c.~1~ 2008-10-28 10:11:30.000000000 -0700
+++ linux-omap-2.6/drivers/serial/8250.c 2008-10-29 08:33:31.000000000 -0700
@@ -483,6 +483,7 @@ static inline int _serial_dl_read(struct
/* Uart divisor latch write */
static inline void _serial_dl_write(struct uart_8250_port *up, int value)
{
+mdelay (2);
serial_outp(up, UART_DLL, value & 0xff);
serial_outp(up, UART_DLM, value >> 8 & 0xff);
}
next reply other threads:[~2008-10-29 16:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-29 16:44 Rick Bronson [this message]
-- strict thread matches above, loose matches on Subject: below --
2008-11-04 21:08 What happened to the serial console on BeagleBoard with 2.6.28-rc2? Rick Bronson
2008-11-04 21:26 ` Tony Lindgren
2008-11-02 18:03 Rick Bronson
2008-11-02 19:26 ` David Brownell
2008-11-02 22:07 ` Tony Lindgren
2008-11-01 22:25 Rick Bronson
2008-11-02 16:03 ` David Brownell
2008-10-28 4:03 Nathan Monson
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