On Wed, 14 Sep 2022, Anders Blomdell wrote: > [ 3.837914] ttyS5: autoconf (0x0000, 0x(____ptrval____)): > [ 3.837918] serial_in(ffffffffb6b98380, 0x01) -> 0x00 > [ 3.838041] serial_out(ffffffffb6b98380, 0x01, 0x00) > [ 3.838104] serial_in(ffffffffb6b98380, 0x01) -> 0x00 > [ 3.838165] serial_out(ffffffffb6b98380, 0x01, 0x0f) > [ 3.838229] serial_in(ffffffffb6b98380, 0x01) -> 0x0f > [ 3.838290] serial_out(ffffffffb6b98380, 0x01, 0x00) > [ 3.838353] serial_in(ffffffffb6b98380, 0x04) -> 0x00 > [ 3.838417] serial_in(ffffffffb6b98380, 0x03) -> 0x00 > [ 3.838479] serial_out(ffffffffb6b98380, 0x03, 0xbf) > [ 3.838541] serial_out(ffffffffb6b98380, 0x02, 0x00) > [ 3.838602] serial_out(ffffffffb6b98380, 0x03, 0x00) > [ 3.838667] serial_out(ffffffffb6b98380, 0x02, 0x01) > [ 3.838731] serial_in(ffffffffb6b98380, 0x02) -> 0xc1 > [ 3.838791] serial_out(ffffffffb6b98380, 0x03, 0x00) > [ 3.838853] serial_out(ffffffffb6b98380, 0x04, 0x00) > [ 3.838891] serial_out(ffffffffb6b98380, 0x02, 0x01) > [ 3.838891] serial_out(ffffffffb6b98380, 0x02, 0x07) > [ 3.838891] serial_out(ffffffffb6b98380, 0x02, 0x00) > [ 3.838891] serial_in(ffffffffb6b98380, 0x00) -> 0x1d > [ 3.838891] serial_out(ffffffffb6b98380, 0x01, 0x00) > [ 3.839232] iir=193 > [ 3.839233] type=16550A > [ 3.839347] 0000:07:00.0: ttyS5 at MMIO 0xe3601200 (irq = 17, base_baud = > 15625000) is a 16550A > [ 3.839424] serial_out(ffffffffb6b98380, 0x04, 0x80) Thank you. I gather your OxSemi devices are ttyS4 and ttyS5, right? So probing doesn't work for some reason and the port isn't even recognised as a 950 device, e.g. I have this for mine: ttyS0: autoconf (0x0000, 0x(____ptrval____)): EFRv2 950id=16:c9:50:0d serial 0000:07:00.3: detected caps 00000700 should be 00000500 iir=193 type=16C950/954 0000:07:00.3: ttyS0 at MMIO 0x60301000 (irq = 26, base_baud = 15625000) is a 16C950/954 I'll examine your I/O conversation log in detail and will see if I can come up with a possible explanation. NB I'm at the GNU Tools Cauldron conference from tomorrow through this coming Monday, so I may not be able to get to the bottom of this issue right away. Maciej
