4 files changed, 55 insertions, 0 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 0d934bfbdd9b..b4b39811b445 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2083,6 +2083,20 @@ static int serial8250_startup(struct uart_port *port)
 
         serial8250_set_mctrl(&up->port, up->port.mctrl);
 
+        /* Serial over Lan (SoL) hack:
+           Intel 8257x Gigabit ethernet chips have a
+           16550 emulation, to be used for Serial Over Lan.
+           Those chips take a longer time than a normal
+           serial device to signalize that a transmission
+           data was queued. Due to that, the above test generally
+           fails. One solution would be to delay the reading of
+           iir. However, this is not reliable, since the timeout
+           is variable. So, let's just don't test if we receive
+           TX irq. This way, we'll never enable UART_BUG_TXEN.
+         */
+        if (up->port.flags & UPF_NO_TXEN_TEST)
+                goto dont_test_tx_en;
+
         /*
          * Do a quick test to see if we receive an
          * interrupt when we enable the TX irq.
@@ -2102,6 +2116,7 @@ static int serial8250_startup(struct uart_port *port)
                 up->bugs &= ~UART_BUG_TXEN;
         }
 
+dont_test_tx_en:
         spin_unlock_irqrestore(&up->port.lock, flags);
 
         /*
diff --git a/drivers/serial/8250_pci.c b/drivers/serial/8250_pci.c
index 536d8e510f66..533f82025adf 100644
--- a/drivers/serial/8250_pci.c
+++ b/drivers/serial/8250_pci.c
@@ -798,6 +798,21 @@ pci_default_setup(struct serial_private *priv,
         return setup_port(priv, port, bar, offset, board->reg_shift);
 }
 
+static int skip_tx_en_setup(struct serial_private *priv,
+                        const struct pciserial_board *board,
+                        struct uart_port *port, int idx)
+{
+        port->flags |= UPF_NO_TXEN_TEST;
+        printk(KERN_DEBUG "serial8250: skipping TxEn test for device "
+                          "[%04x:%04x] subsystem [%04x:%04x]\n",
+                          priv->dev->vendor,
+                          priv->dev->device,
+                          priv->dev->subsystem_vendor,
+                          priv->dev->subsystem_device);
+
+        return pci_default_setup(priv, board, port, idx);
+}
+
 /* This should be in linux/pci_ids.h */
 #define PCI_VENDOR_ID_SBSMODULARIO      0x124B
 #define PCI_SUBVENDOR_ID_SBSMODULARIO   0x124B
@@ -864,6 +879,27 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
                 .init           = pci_inteli960ni_init,
                 .setup          = pci_default_setup,
         },
+        {
+                .vendor         = PCI_VENDOR_ID_INTEL,
+                .device         = PCI_DEVICE_ID_INTEL_8257X_SOL,
+                .subvendor      = PCI_ANY_ID,
+                .subdevice      = PCI_ANY_ID,
+                .setup          = skip_tx_en_setup,
+        },
+        {
+                .vendor         = PCI_VENDOR_ID_INTEL,
+                .device         = PCI_DEVICE_ID_INTEL_82573L_SOL,
+                .subvendor      = PCI_ANY_ID,
+                .subdevice      = PCI_ANY_ID,
+                .setup          = skip_tx_en_setup,
+        },
+        {
+                .vendor         = PCI_VENDOR_ID_INTEL,
+                .device         = PCI_DEVICE_ID_INTEL_82573E_SOL,
+                .subvendor      = PCI_ANY_ID,
+                .subdevice      = PCI_ANY_ID,
+                .setup          = skip_tx_en_setup,
+        },
         /*
          * ITE
          */
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 114b8192eab9..aca8c458aa8a 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -2323,6 +2323,9 @@
 #define PCI_DEVICE_ID_INTEL_82378       0x0484
 #define PCI_DEVICE_ID_INTEL_I960        0x0960
 #define PCI_DEVICE_ID_INTEL_I960RM      0x0962
+#define PCI_DEVICE_ID_INTEL_8257X_SOL   0x1062
+#define PCI_DEVICE_ID_INTEL_82573E_SOL  0x1085
+#define PCI_DEVICE_ID_INTEL_82573L_SOL  0x108F
 #define PCI_DEVICE_ID_INTEL_82815_MC    0x1130
 #define PCI_DEVICE_ID_INTEL_82815_CGC   0x1132
 #define PCI_DEVICE_ID_INTEL_82092AA_0   0x1221
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 90bbbf0b1161..df9245c7bd3b 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -296,6 +296,7 @@ struct uart_port {
 #define UPF_HARDPPS_CD          ((__force upf_t) (1 << 11))
 #define UPF_LOW_LATENCY         ((__force upf_t) (1 << 13))
 #define UPF_BUGGY_UART          ((__force upf_t) (1 << 14))
+#define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 #define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))