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 <dan.j.williams@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/serial/8250_pci.c b/drivers/tty/serial/8250_pci.c
index 8742ef5..2cbf78f 100644
--- a/drivers/tty/serial/8250_pci.c
+++ b/drivers/tty/serial/8250_pci.c
@@ -1118,6 +1118,18 @@
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 @@
.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