From e86ff4a63c9fdd875ba8492577cd1ad2252f525c Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 22 Nov 2011 13:41:29 -0800 Subject: [PATCH] serial/8250_pci: init-quirk msi support for kt serial controller The semantics of UPF_IIR_ONCE (once per serial irq) are only guaranteed if the kt irq is not shared (once per serial isr in the shared case == potentially unwanted reads of the IIR). Signed-off-by: Dan Williams Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250_pci.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/tty/serial/8250_pci.c b/drivers/tty/serial/8250_pci.c index 8742ef5be6ba..2cbf78f77c4a 100644 --- a/drivers/tty/serial/8250_pci.c +++ b/drivers/tty/serial/8250_pci.c @@ -1118,6 +1118,18 @@ pci_xr17c154_setup(struct serial_private *priv, return pci_default_setup(priv, board, port, idx); } +static int try_enable_msi(struct pci_dev *dev) +{ + /* use msi if available, but fallback to legacy otherwise */ + pci_enable_msi(dev); + return 0; +} + +static void disable_msi(struct pci_dev *dev) +{ + pci_disable_msi(dev); +} + #define PCI_VENDOR_ID_SBSMODULARIO 0x124B #define PCI_SUBVENDOR_ID_SBSMODULARIO 0x124B #define PCI_DEVICE_ID_OCTPRO 0x0001 @@ -1233,7 +1245,9 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = { .device = PCI_DEVICE_ID_INTEL_PATSBURG_KT, .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID, + .init = try_enable_msi, .setup = kt_serial_setup, + .exit = disable_msi, }, /* * ITE -- 2.39.2