[CentOS] Centos 7 add-on serial cards

Fred Smith fredex at fcshome.stoneham.ma.us
Mon Jan 29 14:19:44 UTC 2018


On Mon, Jan 29, 2018 at 07:00:02AM -0500, Pete Geenhuizen wrote:
> 
> 
> On 01/28/18 20:15, Fred Smith wrote:
> >On Sun, Jan 28, 2018 at 12:10:29PM -0500, Pete Geenhuizen wrote:
> >>I'm upgrading from CentOS6 to CentOS 7.
> >>
> >>I run 2 weather stations on C6 and have one of them attached to
> >>ttyS0 which is on the motherboard, and the other to ttyS2 which in
> >>on an add-on PCI serial card.
> >>
> >>I'm migrating the weather stations another host running C7 which has
> >>a similar hardware configuration.  When I connect the weather
> >>station to ttyS0 everything works fine, but when I try to use ttyS1
> >>or ttyS2 nothing happens.
> >>
> >>The OS identifies all 3 ports, and I've already tried several
> >>different serial cards several of the slots on the motherboard all
> >>have yielded the same result.  I've even gone so far as to try to
> >>get this to work on another computer running C7 with the same
> >>result, success on ttyS0, but nothing nothing when I try ttyS1 or
> >>ttyS2.
> >>
> >>I'm thinking that this might be a driver issue, but having used
> >>several different cards I'm just not sure.
> >>
> >>Any assistance would be greatly appreciated.
> >>
> >>Pete
> >Wondering if you've tried poking at them with 'setserial'?
> >
> Thanks for the suggestion.
> 
> I looked at them with setserial, but I have no familiarity with the
> program to know what to change.
> 
> setserial -ag /dev/ttyS*
> /dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
>     Baud_base: 115200, close_delay: 50, divisor: 0
>     closing_wait: 3000
>     Flags: spd_normal skip_test
> 
> /dev/ttyS1, Line 1, UART: 16550A, Port: 0x8000, IRQ: 17
>     Baud_base: 115200, close_delay: 50, divisor: 0
>     closing_wait: none
>     Flags: spd_normal skip_test
> 
> /dev/ttyS2, Line 2, UART: 16550A, Port: 0x8400, IRQ: 17
>     Baud_base: 115200, close_delay: 50, divisor: 0
>     closing_wait: none
>     Flags: spd_normal skip_test
> 
> /dev/ttyS3, Line 3, UART: unknown, Port: 0x02e8, IRQ: 3
>     Baud_base: 115200, close_delay: 50, divisor: 0
>     closing_wait: 3000
>     Flags: spd_normal
> 
> I changed the closing_wait: on ttyS1 to match ttyS0, but that didn't
> do anything, so there must be more to it.
> 
> Pete

it has been so many years since I've fooled with a serial port that I
don't remember any details. however, this page may prove helpful, it
appears to contain a lot of potentially useful info:

http://www.tldp.org/HOWTO/Serial-HOWTO-8.html

and also this one (linked from the document above:

http://www.tldp.org/HOWTO/Serial-HOWTO-16.html#slow_

Fred

-- 
---- Fred Smith -- fredex at fcshome.stoneham.ma.us -----------------------------
  "For him who is able to keep you from falling and to present you before his 
 glorious presence without fault and with great joy--to the only God our Savior
 be glory, majesty, power and authority, through Jesus Christ our Lord, before
                     all ages, now and forevermore! Amen."
----------------------------- Jude 1:24,25 (niv) -----------------------------



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