Hi, below patch to fix Fourth port offset of Percom PI7C9X7954 boards. I had a problem using Fourth port on a pci express serial board based on Pericom PI7C9X7954. Reading datasheet I notice a "special" offset assign to this port when used in I/O mode. Offset 0x0 -> UART 0 Offset 0x8 -> UART 1 Offset 0x10 -> UART 2 Offset 0x38 -> UART 3 <<---- This don't follow a logical sequence This patch add a different init to last port, to have right offset. I check also Pericom 7952 and 7958 but that devices follow logical sequence, so they are ok. Regards, Angelo Signed-off-by: Angelo Butti <buttiangelo@xxxxxxxxx> --- linux-4.8.6/drivers/tty/serial/8250/8250_pci.c.orig 2016-11-07 14:10:59.041175535 +0100 +++ linux-4.8.6/drivers/tty/serial/8250/8250_pci.c 2016-11-07 14:21:15.644943937 +0100 @@ -1333,6 +1333,30 @@ return setup_port(priv, port, bar, offset, board->reg_shift); } +static int pci_pericom_setup(struct serial_private *priv, + const struct pciserial_board *board, + struct uart_8250_port *port, int idx) +{ + unsigned int bar, offset = board->first_offset, maxnr; + + bar = FL_GET_BASE(board->flags); + if (board->flags & FL_BASE_BARS) + bar += idx; + else + offset += idx * board->uart_offset; + + if (idx==3) + offset = 0x38; + + maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) >> + (board->reg_shift + 3); + + if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr) + return 1; + + return setup_port(priv, port, bar, offset, board->reg_shift); +} + static int ce4100_serial_setup(struct serial_private *priv, const struct pciserial_board *board, @@ -2284,6 +2308,16 @@ .exit = pci_plx9050_exit, }, /* + * Pericom (Only 7954 - It have a offset jump for port 4) + */ + { + .vendor = PCI_VENDOR_ID_PERICOM, + .device = PCI_DEVICE_ID_PERICOM_PI7C9X7954, + .subvendor = PCI_ANY_ID, + .subdevice = PCI_ANY_ID, + .setup = pci_pericom_setup, + }, + /* * PLX */ { -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html