8250: add support for ASIX devices with a FIFO bug

Information and a different patch provided by <donald@asix.com.tw>. We do
it a little differently to keep the modularity and to avoid playing with
RLSI.

We add a new uart bug for the parity flaw and set it in the pci matches.
If parity check is enabled then we drop the FIFO trigger to 1 as per the
Asix reference code.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index ca42d16e5a121a52f33b471e401d33ee847ade1b..44f52c6f15b9870ad499f1fac41478057ecec268 100644 (file)
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -2202,6 +2202,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
        unsigned char cval, fcr = 0;
        unsigned long flags;
        unsigned int baud, quot;
+       int fifo_bug = 0;
 
        switch (termios->c_cflag & CSIZE) {
        case CS5:
@@ -2221,8 +2222,11 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 
        if (termios->c_cflag & CSTOPB)
                cval |= UART_LCR_STOP;
-       if (termios->c_cflag & PARENB)
+       if (termios->c_cflag & PARENB) {
                cval |= UART_LCR_PARITY;
+               if (up->bugs & UART_BUG_PARITY)
+                       fifo_bug = 1;
+       }
        if (!(termios->c_cflag & PARODD))
                cval |= UART_LCR_EPAR;
 #ifdef CMSPAR
@@ -2246,7 +2250,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 
        if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) {
                fcr = uart_config[port->type].fcr;
-               if (baud < 2400) {
+               if (baud < 2400 || fifo_bug) {
                        fcr &= ~UART_FCR_TRIGGER_MASK;
                        fcr |= UART_FCR_TRIGGER_1;
                }

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index f9719d167c8d74f3159d995b09899bc52eab8294..c335b2b23a5f9757d8d6caa1ab12442e4509a18c 100644 (file)
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -78,6 +78,7 @@ struct serial8250_config {
 #define UART_BUG_TXEN  (1 << 1)        /* UART has buggy TX IIR status */
 #define UART_BUG_NOMSR (1 << 2)        /* UART has buggy MSR status bits (Au1x00) */
 #define UART_BUG_THRE  (1 << 3)        /* UART has buggy THRE reassertion */
+#define UART_BUG_PARITY        (1 << 4)        /* UART mishandles parity if FIFO enabled */
 
 #define PROBE_RSA      (1 << 0)
 #define PROBE_ANY      (~0)

diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 2ef9a075eec5f3bf9b986833fa894ce15693c1b1..62e10fe747a8756e3826400c375dba876f3c43ea 100644 (file)
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1032,8 +1032,15 @@ static int pci_oxsemi_tornado_init(struct pci_dev *dev)
        return number_uarts;
 }
 
-static int
-pci_default_setup(struct serial_private *priv,
+static int pci_asix_setup(struct serial_private *priv,
+                 const struct pciserial_board *board,
+                 struct uart_8250_port *port, int idx)
+{
+       port->bugs |= UART_BUG_PARITY;
+       return pci_default_setup(priv, board, port, idx);
+}
+
+static int pci_default_setup(struct serial_private *priv,
                  const struct pciserial_board *board,
                  struct uart_8250_port *port, int idx)
 {
@@ -1187,6 +1194,7 @@ pci_xr17c154_setup(struct serial_private *priv,
 #define PCIE_DEVICE_ID_NEO_2_OX_IBM    0x00F6
 #define PCI_DEVICE_ID_PLX_CRONYX_OMEGA 0xc001
 #define PCI_DEVICE_ID_INTEL_PATSBURG_KT 0x1d3d
+#define PCI_VENDOR_ID_ASIX             0x9710
 
 /* Unknown vendors/cards - this should not be in linux/pci_ids.h */
 #define PCI_SUBDEVICE_ID_UNKNOWN_0x1584        0x1584
@@ -1726,7 +1734,17 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
                .subvendor      = PCI_ANY_ID,
                .subdevice      = PCI_ANY_ID,
                .setup          = pci_omegapci_setup,
-        },
+       },
+       /*
+        * ASIX devices with FIFO bug
+        */
+       {
+               .vendor         = PCI_VENDOR_ID_ASIX,
+               .device         = PCI_ANY_ID,
+               .subvendor      = PCI_ANY_ID,
+               .subdevice      = PCI_ANY_ID,
+               .setup          = pci_asix_setup,
+       },
        /*
         * Default "match everything" terminator entry
         */