Thu, Feb 22, 2024 at 10:21:38AM +0100, Federico Vaga kirjoitti:
> Dear all,
>
> My previous email might got lost in some inbox. Allow me to retry to ping you to
> get some help in configuring the MOXA CP-132EL using the 8250 driver.
You need to Cc maintainers and relevant developers.
> On Mon, Jan 22, 2024 at 11:52:15AM +0100, Federico Vaga wrote:
> > Dear all,
> >
> > I'm having problems in trying to use the MOXA CP-132EL card with the 8250 driver
> > on the stable kernel 5.10.192 (but I also tried the 6.1.70). It seems not to
> > work. As a note, to do my tests, I have a loop cable connecting the two on-board
> > serial ports.
> >
> > I see this device should be supported by the 8250 code, in particular this
> > appears in 8250_pci.c
> >
> > ```
> > $ git grep 132EL drivers/tty/
> > drivers/tty/serial/8250/8250_pci.c:#define PCI_DEVICE_ID_MOXA_CP132EL 0x1322
> > drivers/tty/serial/8250/8250_pci.c: { PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP132EL), pbn_moxa_2 },
> > ```
> >
> > At boot time the device is correctly discovered, and it matches the driver.
> > Indeed two new tty interfaces appear under `/dev`
> >
> > ```
> > $ dmesg | grep 0d:00.0
> > [ 0.196175] pci 0000:0d:00.0: [1393:1322] type 00 class 0x070002
> > [ 0.196350] pci 0000:0d:00.0: reg 0x10: [io 0x4000-0x403f]
> > [ 0.196448] pci 0000:0d:00.0: reg 0x14: [mem 0xb0100000-0xb0100fff]
> > [ 0.196534] pci 0000:0d:00.0: reg 0x18: [io 0x4040-0x404f]
> > [ 0.197474] pci 0000:0d:00.0: supports D1 D2
> > [ 0.197475] pci 0000:0d:00.0: PME# supported from D3hot
> > [ 0.371301] 0000:0d:00.0: ttyS2 at MMIO 0xb0100000 (irq = 16, base_baud = 921600) is a ST16650
> > [ 0.371832] 0000:0d:00.0: ttyS3 at MMIO 0xb0100200 (irq = 16, base_baud = 921600) is a ST16650
> >
> > ```
> >
> > The communication seems not to work. However, the communication works when using
> > the driver provided by MOXA (``mxupcie.ko``).
Shouldn't we use mxser in the kernel for MOXA?
{ PCI_DEVICE_DATA(MOXA, CP132, 2) },
> > The interesting thing is the following. Binding back the device to the 8250
> > serial driver after having loaded first the mxupcie makes it work. Translated
> > into a procedure:
> >
> > 1. load 8250 serial driver
> > 2. make a test (FAIL)
> > 3. unbind device from 8250
> > 4. load mxupcie driver
> > 5. unbind device from mxupcie
> > 6. bind device to 8250
> > 7. make a test (SUCCESS)
> >
> > This made me think of two possible cases:
> >
> > 1. mxupcie applies a default serial configuration that works out-of-the-box
> > 2. mxupcie perform a hardware configuration that the 8250 is not doing
> >
> >
> > About option (1) I used ``stty -g`` to compare configurations right after
> > binding. But it seems exactly the same when using 8250 or mxupcie from MOXA.
> >
> >
> > ``` Using 8250
> > # stty -F /dev/ttyS3 -g
> > 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0
> > # stty -F /dev/ttyS2 -g
> > 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0
> > ```
> >
> > ``` Using mxupcie
> > # stty -F /dev/ttyMUE0 -g
> > 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0
> > # stty -F /dev/ttyMUE1 -g
> > 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0
> > ```
> >
> > This makes me think that probably option (2) represents the problem, but due to
> > my limited knowledge with these two drivers (8250, mxupcie) and the device
> > (CP-132EL) I can not spot the problem in the code.
> >
> > Therefore, I'm asking you: are you aware of such a problem with this card or
> > others from MOXA? Is there someone in the community who is using the 8250 driver
> > with MOXA devices?
--
With Best Regards,
Andy Shevchenko
