i386/105616: UART PCI device just silent...
Marcel Moolenaar
xcllnt at mac.com
Tue Nov 28 13:50:30 PST 2006
The following reply was made to PR i386/105616; it has been noted by GNATS.
From: Marcel Moolenaar <xcllnt at mac.com>
To: Helge Oldach <puc-uart at oldach.net>
Cc: FreeBSD-gnats-submit at FreeBSD.org
Subject: Re: i386/105616: UART PCI device just silent...
Date: Tue, 28 Nov 2006 13:47:06 -0800
On Nov 28, 2006, at 1:38 PM, Helge Oldach wrote:
> Hi Marcel,
>
>>> It seems that setting clock rate on this board does not work
>>> properly, but instead some default non-standard value remains set
>>> forever...
>> Interesting. The uart(4) driver in -STABLE writes the baudrate in a
>> single 16-bit wide operation. The uart(4) driver in -CURRENT
>> doesn't do
>> that. Could you try the attached patch?
>
> Works, problem fixed. I now can talk uart(4) just identical to sio(4).
> Ah, finally no silo overflows any more!
Excellent. Good news. Thanks for testing.
> BTW, I applies to most 8250/16550 based PCI board, so it should
> probably
> be fixed before 6.2-STABLE, IMHO.
I agree. I will work on that right away.
> BTW2, still the SUN1889 is recognized as 16550, not 16650. This has
> probably no impact since it only means we do not utilize the full FIFO
> depth of the 16650, but still...
The type is determined based on the FIFO size. Apparently, the FIFO size
is 16 bytes and not 32 bytes. I don't know why this is. Maybe we need to
set a special bit to "enable" the full FIFO size. However, this would
not be compatible with 16650 UARTs. It remains a mystery...
Thanks again for getting this problem resolved!
--
Marcel Moolenaar
xcllnt at mac.com
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